Vertebral stabilization assembly and method

ABSTRACT

A vertebral stabilization assembly for stabilizing vertebrae is provided. The vertebral stabilization assembly includes a first and a second pedicle screw, a first and second connecting screw, and a connecting member. The first and second pedicle screws each have a shaft provided with a threaded portion operable for threading engagement of the first and second pedicle screws with a first and second vertebra, respectively, each shaft also has an engaging portion. The first and second connecting screws each have a first end adapted to be received by the engaging portions of the first and second pedicle screws, respectively. The connecting member has a first end connected to the first connecting screw and a second end connected to the second connecting screw for stabilization of the first and second vertebra. A guide member for placement of the connecting screw and method for anteriorly stabilizing vertebrae is also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. § 120, this divisional application claims priorityfrom, and hereby incorporates by reference for all purposes, copendingU.S. patent application Ser. No. 10/109,172, entitled VertebralStabilization Assembly and Method, naming Paul A. Vaughan as inventor,filed Mar. 28, 2002, which, pursuant to 35 U.S.C. § 119(e), claims thebenefit of U.S. Provisional Patent Application No. 60/327,118, entitledVertebral Stabilization Assembly and Method, filed Oct. 3, 2001, andU.S. Provisional Patent Application No. 60/350,259, entitled VertebralStabilization Assembly and Method Having a Modified Pedicle Screw, filedNov. 2, 2001, and U.S. Provisional Patent Application No. 60/331,857entitled Vertebral Stabilization Assembly and Method for AnteriorPlacement, filed Nov. 20, 2001, and U.S. Provisional Patent ApplicationNo. 60/353,691, entitled Vertebral Stabilization Assembly and MethodHaving Dual Pedicle Screws, filed Jan. 31, 2002, all naming Paul A.Vaughan as inventor, which are hereby incorporated by reference for allpurposes.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to a spinal stabilization andmore specifically, but not by way of limitation, to a vertebralstabilization assembly and method for stabilizing vertebra.

BACKGROUND OF THE INVENTION

The human spine frequently requires surgery to repair deformities orinjuries. Spinal problems may be caused by a trauma to the spinereceived during an accident, excessive strain or stress on the spinefrom physical activities, a sedentary lifestyle and poor posture thatmay place abnormal pressure on the spine, disease or a variety of otherreasons. Spinal fusion is a common surgery intended to alleviate paincaused by these spinal deformities or injuries.

The spinal fusion procedure generally includes removing the disk,packing bone graft between the vertebrae and placing a spinal implant,such as screws attached to a plate, rod or cage, to fuse elements of thespine together. Once the disk is removed and the bone graft is placedbetween the vertebrae, the bone graft will fuse to the vertebrae over aperiod of several months following the surgery.

The purpose of the plate is to stabilize the vertebrae until the bonegraft has become fused to the vertebrae. The plate is positioned toextend between at least two vertebrae. The plate is attached to screwsanchored in each of the adjacent vertebrae, thus immobilizing thedesired portion of the spine. The plate is anchored to the screws eitheron the front, anterior, or back, posterior, sides of the vertebrae.

The present invention is not intended to be limited to applications in aspecific region of the spine, and may, in fact, be utilized equally wellwith the cervical, thoracic, lumbar and sacrum vertebrae of the spine.However, for purposes of explanation, the surgical procedure will bediscussed in greater detail with respect only to the lumbar vertebraeregion of the spine. Procedurally, anterior, or entry from the stomachregion of the patient, lumbar vertebra surgery provides the surgeon withoptimum access to the entire intervertebral disk. Posterior, or entryfrom the back of the patient, surgery is less preferred since access tothe disk is restricted. Once the anterior lumbar discectomy, or removalof the lumbar disk, is completed, the bone graft is placed into thespace between the vertebrae previously occupied by the disk.

The patient is then positioned for posterior fusion, or placement, ofthe plate. The stabilization is typically accomplished by placing ascrew in each of the lumbar vertebra such the screw extends through aportion of the vertebra and into the body of the vertebra. Each screwextends posteriorly from the vertebra sufficient for attachment to theplate. The plate is then anchored to each of the screws to retain theadjacent lumbar vertebrae positioned a distance from each other. Theplate and screws thereby stabilize the lumbar vertebrae and provide timefor the vertebrae and bone graft to fuse into a solitary unit.

However, posterior fusion requires large posterior muscle dissection tosafely implant the pedicle screws and provide for placement of theplate. Such major muscle damage presents a danger to the patient duringsurgery from infection and the extensive muscle damage. Also, additionaltime is required to perform both extensive anterior and posteriorsurgical portions. The added surgical time presents another risk to thepatient.

Attempts to eliminate the negative aspects of posterior fusion includeanterior placement of the plate and screws. Although anterior fusionavoids the problems associated with the larger posterior fusion,additional problems arise. In such systems, the anchoring-screws arelaterally placed on the anterior of the vertebra. Lateral placementrequires a significantly more invasive procedure and much greaterexposure. Also, screws anchored laterally through the anterior of thevertebra do not provide the stability of those extending posteriorlythrough the pedicle and into the vertebral body. Furthermore,anteriorly-anchored screws do not promote quick and uniform fusion ofthe bone graft to the vertebra since they do not have the stability ofthe pedicle fixation.

Thus a need exists for a vertebral stabilization assembly that obtainsthe benefits while overcoming the disadvantages of prior procedures andsystems.

SUMMARY OF THE INVENTION

The present invention provides a vertebral stabilization assembly forstabilizing vertebra. The vertebral stabilization assembly includes afirst and a second pedicle screw, a first and a second connecting screwand a connecting member. The first pedicle screw has a shaft providedwith a threaded portion operable for threading engagement of the firstpedicle screw with a first vertebra, the shaft also has an engagingportion. The first connecting screw has a first end adapted to bereceived by the engaging portion of the first pedicle screw.

The second pedicle screw has a shaft provided with a threaded portionoperable for threading engagement of the pedicle screw with a secondvertebra. The shaft of the second pedicle screw has an engaging portion.The second connecting screw has a first end adapted to be received bythe engaging portion of the second pedicle screw. The connecting memberhas a first end and the second end. The first end of the connectingmember connected to the first connecting screw positionable in the firstvertebra. The second end of the connecting member connected to thesecond connecting screw positionable in the second vertebra forstabilization of the first vertebra and the second vertebra.

In one aspect, the connecting member may be a rod, bracket, plate orbrace. In other aspects, the first and second connecting screws are eachprovided with an opening in a second end thereof and wherein the firstend of the rod is positionable in the opening in the second end of thefirst connecting screw and wherein the second end of the rod ispositionable in the opening in the second end of second connectingscrew.

In one aspect, the present invention further comprises a first andsecond tensioning mechanism, the first tensioning mechanism tensioninglyengaging the first end of the rod in the opening in the second end ofthe first connecting screw and the second tensioning mechanismtensioningly engaging the second end of the rod in the opening in thesecond end of the second connecting screw.

In other aspects, the first and second connecting screws are providedwith coupling portions operable to couple the first and secondconnecting screws with the connecting member. In other aspects, thecoupling portions of the first and second connecting screws are furtherdefined as a threaded end of the first and second connecting screws.

In other aspects, the threaded end of the first and second connectingscrews are connectable to the connecting member by bolts. While in otheraspects, the connecting member connected to the first and secondconnecting screw is sized to retain the first vertebra disposed adistance from the second vertebra. The connecting member may be sized toretain the first vertebra disposed so as to prevent contact with thesecond vertebra.

In other aspects, the first and second pedicle screws are operable toengage a first and second lumbar vertebra, respectively.

In yet another aspect the vertebral stabilization assembly furtherincludes a bore screw having a shaft sized similar in diameter to theshaft of the first and second pedicle screw. In one aspect, the diameterof the shaft of the bore screw is substantially similar to the diameterof the shaft of the pedicle screw, while in other aspects the diameterof the shaft of the bore screw is smaller, and in others larger, thanthe diameter of the shaft of the pedicle screw The bore screw isoperative to bore an opening in the vertebra, from the posterior side ofthe vertebra.

The bore screw is useful to create a bore opening in the vertebra thatis at a desirable angle in the vertebra. The bore screw may then belocated from the anterior side and removed anteriorly according to oneaspect or removed posteriorly according to another aspect of the presentinvention. Where the bore screw is removed anteriorly, the bore screw isprovided with an engaging portion on a distal end of the bore screw forconnection of the bore screw by a tool for removal from the vertebralanterior.

One advantage of utilizing the bore screw is that the angle of placementof the bore screw is known so that the proper pedicle screw may beselected based on the angle of penetration of the bore opening createdin the vertebra by the bore screw, such as a pedicle screw having aengaging portion with the proper angle of connection for attachment ofthe connecting screw and a pedicle screw of appropriate length.

In another aspect, the vertebral stabilization assembly of the presentinvention further includes an indicator positionable posteriorlyadjacent the bore opening created by bore screw. The indicatorindicating the location of the bore opening from the anterior side ofthe vertebra. In one aspect, the indicator is an LED (light emittingdiode) disposed on a rigid shaft extendable down the bore opening nearthe anterior side of the vertebra. In other aspects, the shaft may besubstantially flexible for easy removal. In other aspects, the indicatoris an LED or higher intensity light, such as a laser light, and isdisposed posteriorly near the bore opening such that the light projectsdown the opening and is perceptible from the vertebral anterior.

In another aspect the present invention provides a pedicle screw forsecuring a connecting screw of a vertebral stabilization assembly. Thepedicle screw includes a shaft, an engaging portion and couplingportion. The shaft has a threaded portion operable for threadingengagement of the pedicle screw with a vertebra. The engaging portion isprovided on the shaft and operable to receive a connecting screw of thevertebral stabilization assembly. The coupling portion is provided onthe shaft and adapted to connect a guide member of the vertebralstabilization assembly. In one aspect of the pedicle screw of thepresent invention the shaft is cannulated. The cannulated portion of theshaft further defined as a passageway extending through the shaft from afirst end of the shaft to a second end of the shaft.

In one aspect, the shaft is further defined as having a first end and asecond end such that the threaded portion is adjacent the first end andthe second end is operable to receive rotational engagement for rotatingthe pedicle screw. In yet another aspect, the engaging portion isfurther defined as an opening on the shaft operable to receive theconnecting screw of the vertebral stabilization assembly.

In other aspects, the opening is further defined as extending throughthe shaft from a shaft first side to a shaft second side. In anotheraspect, the opening is coupleable with the connecting screw to providestabilizing engagement of the connecting screw. While yet other aspectsprovide the opening is coupleable with the connecting screw to providerigid engagement with the connecting screw.

In one aspect, the engaging portion is coupleable with the connectingscrew to provide locking engagement with the connecting screw. In otheraspects, the engaging portion is coupleable with the connecting screw toprovide threaded engagement with the connecting screw. In yet otheraspects, the coupling portion of the shaft is associated with theopening in the shaft such when the guide member is coupled to thecoupling portion an alignment member of the guide member is aligned withthe engaging portion in the shaft.

In one aspect, the coupling portion is further defined as an openingoperable for threading engagement. In another aspect, the shaft isfurther defined as a substantially rigid shaft constructed from amaterial selected from the group consisting of steel, aluminum, metallicmaterials and polymeric materials. While in other aspects, the shaft issubstantially cannulated such that a passageway extends through theshaft from a first end of the shaft to a second end of the shaft. In oneaspect, the pedicle screw is operable to engage a lumbar vertebra. Inanother aspect, the pedicle screw is further operable to engage athoracic vertebra.

In one aspect, the engaging portion on the shaft of the pedicle screwincludes rotational portion for rotating the engaging portion forreceiving the connecting screw at various angles relative to the shaftof the pedicle screw. In some aspects, the rotational portion includes ahinging member or a ratcheting member operative for rotation of theengaging portion. In other aspects, the engaging portion is disposed inan engaging opening in the shaft of the pedicle such that the engagingportion is rotatable within the engaging opening and, in some aspects,becomes fixed or locked when the connecting screw is received by theengaging portion.

In one aspect, the shaft of the pedicle screw is provided with at leastone non-continuous thread extending circumferentially about the shaftsuch that at least one gap is disposed between a first portion of thenon-continuous thread and a second portion of the non-continuous thread.The advantage of the disposition of the non-continuous thread is thatwhen the nerve is aggravated by the placement of the pedicle screw, thepedicle screw may be rotated into a position such that the gap isadjacent the aggravated nerve instead of the thread to alleviate theaggravation which may be caused by the threaded portion of the shaft ofthe pedicle screw.

In another aspect, the shaft of the pedicle screw is provided with afirst threaded portion and a reinforced portion. The reinforced portionof the shaft has a diameter that is greater than a diameter of the firstthreaded portion of the shaft. In one aspect, the reinforced portion ofthe shaft is substantially adjacent the engaging portion of the shaftfor reinforcing the connection of the connecting screw to the pediclescrew via the engaging portion.

In another aspect the reinforced portion of the shaft is adjacent thefirst threaded portion and adjacent a second threaded portion, thediameter of the reinforced portion is greater than the diameter of thefirst threaded portion and about equal to a diameter measured from anoutermost edge of a plurality of threads provided on the first threadedportion of the shaft. The diameter of the reinforced portion of theshaft is less than a diameter measured from an outermost edge of aplurality of threads provided on the second threaded portion of theshaft. The reinforced portion of the shaft is one advantage of thepresent aspect since the stability of the vertebral stabilizationassembly is significantly enhanced by the additional structural supportprovided by the reinforced portion for connection of the connectingscrew to the engaging portion of the pedicle screw adjacent thereinforced portion.

In yet another aspect, the shaft of the pedicle screw has at least afirst groove extending a distance along the length of the shaft. In oneaspect, a distal end of the shaft of the pedicle screw is substantiallyconical, while in other aspects, the distal end of the shaft is asubstantially flat surface. In one aspect, where the distal end of theshaft is a substantially flat surface, the pedicle screw is providedwith a cap which may have a conically shaped first end and a second endconfigured for mating connection near the distal end of the pediclescrew. In this aspect, the mating connection may be achieved byproviding a recess in at least the first groove on the shaft and a notchon an inner surface of the cap such that the notch on the inner surfaceof the cap is tensioningly received by the recess in at least the firstgroove of the shaft.

In one aspect, the distal end of the pedicle screw is rectangularlyconfigured for mating with a guide member for proper alignment of theengaging portion of the pedicle screw for connection of the connectingscrew. In one aspect, only a portion of the shaft is provided withthreads. In this aspect, the threads may be provided except on a portionof the shaft substantially adjacent the engaging portion. In otheraspects, only a portion of the shaft above the engaging portion isprovided with threads, while in other aspects only a portion of theshaft below the engaging portion is provided with threads.

In yet another aspect, the pedicle screw has a first end provided with ahead operative for rotational engagement of the pedicle screw with thevertebra. A coupling portion is disposed adjacent the first end thepedicle screw and is further operative to engage a guide member of thevertebral stabilization assembly. In this aspect, the pedicle screw isprovided for anterior placement such that a distal end of the pediclescrew which initially penetrates the vertebra from an anterior side ofthe vertebra engages and stabilizes from within the body portion of thevertebra near the pedicle of the vertebra. After placement of thepedicle screw, the head of the pedicle screw is disposed adjacent theanterior side of the vertebra for receiving a guide member.

One advantage of the pedicle screw for anterior placement andstabilization is that, when utilizing this aspect of the pedicle screw,placement of the vertebral stabilization assembly may be accomplishedentirely from the patient's anterior eliminating the need to rotate thepatient and further reducing the time needed for the surgical procedure.Utilizing the present aspect of the pedicle screw for anterior placementand stabilization provides numerous advantages even where portions ofthe medical procedure are accomplished from the patient's posterior. Forexample, in some aspects, it may be useful and necessary to rotate thepatient and perform significant or peripheral procedures from thepatient's posterior during certain portions of the vertebralstabilization procedure.

In yet other embodiments, the present invention provides a toolconfigured to connect to the distal end of the pedicle screw. In oneaspect, the tool is provided with a first end having a handle adapted tobe grasped by the hand of an individual and a second end provided with aconnector to connect to the distal end of the pedicle screw to retainand stabilize the pedicle screw for placement and removal of theconnecting screw. In one aspect the distal end of the pedicle screw isprovided with an opening and the second end of the tool is provided witha connector configured to be received into the opening in the distal endof the pedicle screw for securing the pedicle screw.

In yet another aspect, the connecting screw is provide with at least afirst groove on a shaft portion of the connecting screw for connectionby a tool for retaining the connecting screw for placement and removalof the connecting screw. In one aspect, the connecting screw has anopening on one end of the connecting screw, and the tool is providedwith a connector adapted to be received by the opening and configured toconnect to the tool.

In yet another aspect, the present invention provides a guide member forplacement of a screw of a vertebral stabilization assembly. The guidemember including a coupling portion, and offset member, and an alignmentmember. The coupling portion is operable to couple with a couplingportion of a pedicle screw of the vertebral stabilization assembly. Theoffset member is connected to the coupling portion of the guide member.The offset member extending from the coupling portion relative to theconnection of the coupling portion of the guide member to the couplingportion of the pedicle screw. The alignment member is connected to theoffset member. The alignment member is operable for alignment of theconnecting screw of the vertebral stabilization assembly with a portionof the pedicle screw of the vertebral stabilization assembly.

In one aspect, the coupling portion of the guide member is operable tocouple with the coupling portion of the pedicle screw such that theoffset member extends in a predetermined direction relative to thecoupling of the coupling portion of the guide member to the couplingportion of the pedicle screw. While in other aspects, the offset memberis further provided with a first end and a second end, and wherein thefirst end of the offset member is connected to the coupling portion andwherein the second end of the offset member is coupled to the alignmentmember.

In one aspect, the offset member is positionable relative to thecoupling of the coupling portion with the end portion of the pediclescrew. While in other aspects, the offset member extends from thecoupling portion adjacent a shaft portion of the pedicle screw.

In one aspect, the coupling portion of the guide member couples to thecoupling portion of the pedicle screw such that the offset memberpositions the alignment member connected to the offset membersubstantially aligned adjacent a portion of the pedicle screw. In yetanother aspect, the alignment member substantially aligns adjacent tothe engaging portion of a shaft of the pedicle screw. While yet in otheraspects, the alignment member substantially aligns adjacent an openingon the shaft of the pedicle screw. In yet another aspect, the alignmentmember provides alignment for threadingly taping the vertebra adjacentthe opening in the pedicle screw.

In one aspect, the alignment member provides alignment for attachment ofthe connecting screw of the vertebral stabilization assembly to thepedicle screw. In other aspects, the alignment member is further definedas tubular member having a first end, a second end and a openingextending through the tubular member from the first end to the secondend. While in yet other aspects, the opening extending through thetubular member is provided with a diameter sufficient to receive theconnecting screw of the vertebral stabilization assembly through theopening in the tubular member for alignment with an engaging portion ofa shaft of the pedicle screw of the vertebral stabilization assembly.

In another aspect, the present invention provides a vertebralstabilization assembly having dual pedicle screws including a firstpedicle, a second pedicle screw and a connecting screw. The firstpedicle screw has a shaft provided with a threaded portion operable forthreading engagement of the first pedicle screw with a first vertebra.The shaft of the first pedicle screw has an engaging portion.

The second pedicle screw has a shaft provided with a threaded portionoperable for threading engagement of the second pedicle screw with thefirst vertebra, the shaft of the second pedicle has an engaging portion.The connecting screw has a first end and a shaft, the first end of theconnecting screw is adapted to be received by the engaging portion ofthe first pedicle screw. The shaft of the connecting screw is adaptedfor connection to the engaging portion of the second pedicle screw.

In yet another aspect, the present invention provides a method forstabilizing a lower vertebra and an upper vertebra from an anterior sideof the vertebrae using a vertebral stabilization assembly. The methodincludes inserting a first pedicle screw into the lower vertebra througha pedicle and a vertebral body of the lower vertebra from a posteriorside of the lower vertebra. The pedicle screw includes a shaft providedwith a threaded portion operable to threadingly engage the lowervertebra. The shaft of the first pedicle screw has an engaging portionoperable to receive a first connecting screw. The shaft of the firstpedicle screw having a coupling portion operable to couple with a guidemember of the vertebral stabilization assembly.

The method includes inserting a second pedicle screw into an uppervertebra through a pedicle and a vertebral body of the upper vertebrafrom a posterior side of the upper vertebra. The second pedicle screwincludes a shaft provided with a threaded portion operable tothreadingly engage the upper vertebra. The shaft of the second pediclescrew has an engaging portion operable to receive a second connectingscrew. The shaft to the second pedicle screw has a coupling portionoperable to couple with a guide member of the vertebral stabilizationassembly. The method further includes locating the coupling portion ofthe shaft of the first pedicle screw from an anterior side of the lowervertebra.

The method includes coupling the guide member to the coupling portion ofthe shaft of the first pedicle screw from the anterior side of the lowervertebra. The method further provides for inserting a lower connectingscrew through the anterior side of the lower vertebra using the guidemember. The lower connecting screw includes a first end adapted to bereceived by the engaging portion of the first pedicle screw and a secondend adapted to reside outside the lower vertebra on an anterior side ofthe lower vertebra.

The method includes locating the coupling portion of the shaft to thesecond pedicle screw from an anterior side of the upper vertebra. Themethod provides for coupling the guide member to the coupling portion ofthe shaft to the second pedicle screw from the anterior side of theupper vertebra. The method further includes inserting an upperconnecting screw through the anterior side of the upper vertebra usingthe guide member. The upper connecting screw includes a first endadapted to be received by the engaging portion of the second pediclescrew and a second end adapted to reside outside the upper vertebra onthe anterior side of the upper vertebra.

The method also provides for connecting the second end of the lowerconnecting screw of the lower vertebra to the second end of the upperconnecting screw of the upper vertebra. In one aspect, the first andsecond pedicle screws are posteriorly placed on the right side of thelower and upper vertebra, respectively, and wherein the lower and uppervertebra are further defined as a lower and upper lumbar vertebra. Inanother aspect, the first and second pedicle screws are posteriorlyplaced on the right side of the lower and upper vertebra, respectively,and wherein the lower and upper vertebra are further defined as a lowerand upper thoracic vertebra.

In one aspect, the present invention is directed to a method of anteriorvertebral stabilization including placing from the patient's anteriorthe pedicle screw such that a portion of the pedicle screw is stabilizedin a pedicle portion of the vertebra.

In one aspect, the first pedicle screw is further provided with acannulated shaft having a passageway extending from a first end to asecond end of the first pedicle screw and wherein locating the couplingportion of the shaft of the first pedicle screw from the anterior sideof the lower vertebra further provides for extending a tool operable todrill through a portion of the lower vertebra through the passageway ofthe shaft of the first pedicle screw and drilling the portion of thelower vertebra such that the tool extends at least partially through theanterior side of the lower vertebra.

In one aspect, the second pedicle screw is further provided with acannulated shaft having a passageway extending from a first end to asecond end of the second pedicle screw and wherein locating the couplingportion of the shaft of the second pedicle screw from the anterior sideof the upper vertebra further includes extending the tool operable todrill through a portion of the upper vertebra through the passageway ofthe shaft of the second pedicle screw and drilling the portion of theupper vertebra such that the tool extends at least partially through theanterior side of the upper vertebra.

In other aspects, coupling the guide member to the first and secondpedicle screws further includes threadingly coupling the guide member tothe coupling portion of the shaft of the first and second pediclescrews. In another aspect, coupling the guide member to the first andsecond pedicle screws further includes matingly coupling the guidemember to the coupling portion of the shaft of the first and secondpedicle screws.

In one aspect, inserting the lower connecting screw further includespositioning the lower connecting screw in alignment with the engagingportion of the first pedicle screw utilizing an alignment member of theguide member and threading the lower connecting screw through anteriorside of the lower vertebra.

In one aspect, positioning the lower connecting screw in alignment withthe engaging portion of the first pedicle screw further includesreceiving the lower connecting screw by the alignment member of theguide member, the guide member adapted to position the alignment memberconnected thereto the guide member substantially aligned adjacent theengaging portion of the first pedicle screw.

In other aspects, inserting the upper connecting screw further includespositioning the upper connecting screw in alignment with the engagingportion of the second pedicle screw utilizing the alignment member ofthe guide member and threading the upper connecting screw throughanterior side of the upper vertebra.

In one aspect, positioning the upper connecting screw in alignment withthe engaging portion of the second pedicle screw further includesreceiving the upper connecting screw by the alignment member of theguide member, the guide member adapted to position the alignment memberconnected thereto the guide member substantially aligned adjacent theengaging portion of the second pedicle screw.

In another aspect, connecting the upper connecting screw to the lowerconnecting screw further includes, providing a connecting member havinga first end and a second end, connecting the second end of the lowerconnecting screw to the first end of the connecting member andconnecting the second end of the upper connecting screw to the secondend of the connecting member.

In yet another aspect, the connecting member is a plate and wherein thesecond end of the lower connecting screw receives the first end of theplate and wherein the second end of the upper connecting screw receivesthe second end of the plate.

In yet another aspect, the connecting member is a bracket and whereinthe second end of the lower connecting screw receives the first end ofthe bracket and wherein the second end of the upper connecting screwreceives the second end of the bracket. While in other aspects, theconnecting member is a rod and wherein the second end of the lowerconnecting screw connects to the first end of the rod and wherein thesecond end of the upper connecting screw connects to the second end ofthe rod.

The pedicle screw of the present invention advantageously provides forposterior placement of the pedicle screw through a pedicle portion ofthe vertebra for secure attachment of the pedicle screw to the vertebra.The cannulated shaft of the pedicle screw is adapted to receive a drillbit there through such that the drill bit may be caused to drill throughto the anterior side of the vertebra for easily locating the shaft ofthe pedicle screw. Another advantage of the present invention is thatthe pedicle screw is adapted for posterior placement through a pedicleportion of the vertebra for maximum stabilization. The connecting screwof the vertebral stabilization assembly is adapted to engage theengaging portion provided on the shaft of the pedicle screw to furtherpromote a stable engagement of the vertebral stabilization assembly.

Yet another advantage of the present invention is that the engagement ofthe engaging portion of the shaft of the pedicle screw with theconnecting screw prevents the pedicle screw or the connecting screw frommoving or backing out of the vertebra since the connecting screw andpedicle screw are connected to one another.

Another advantage to the present invention is that the added stabilityof the pedicle screw posteriorly placed and connected to the connectingscrew anteriorly insures for maximum stabilization and attachment of theconnecting member and thus greater vertebral stabilization. Anotheradvantage to the present invention is that the pedicle screw may bepercutaneously placed by making only a small posterior incision and thusovercoming the disadvantages associated with posterior fusion requiringlarge posterior muscle dissection and the problems associated therewith.For this reason, the present invention is safer for the patient.

Anterior stabilization via connection to posteriorly placed pediclescrews has numerous advantages including significantly reducing thetotal time required for the surgical procedure. Avoidance of the radicalmuscle dissection required for posterior connection and stabilization isone factor in reducing the time to perform the surgery to about 2.5hours versus the 5 to 7 hours such a procedures ordinarily requires.Thus, anterior stabilization via connection to posteriorly placedpedicle screws provides numerous advantages over prior vertebralstabilization systems and methods.

As well as being placed percutaneously, the pedicle screw may bepositioned so that a head of the pedicle screw is substantially flushwith the surface bone of the vertebra. Such placement further reducesinterference with back muscles and associated problems and presentsanother advantage according to one aspect of the present invention.

Another advantage is that the present invention allows for the drill bitto be disposed within the cannulated portion of the shaft of the pediclescrew for only minor penetration of the surface of the anterior side ofthe vertebra to avoid the risk of damage to soft tissue adjacent theanterior of the vertebra.

Another advantage of the present invention is that the guide memberallows for alignment of the connecting screw with the engaging portionof the pedicle screw without the necessity for time-consuming andinaccurate x-rays, MRI's, or other similar scanning or locating devices.

Another advantage of the present invention is that the method providesfor placement of the vertebral stabilization assembly on an anteriorside of the vertebrae eliminating many of the problems inherent inposterior fusion. Furthermore, elimination of the posterior fusionsubstantially reduces the amount of time required to perform thestabilization procedure according to the present invention.

Another advantage of the present invention is that by posteriorplacement of the pedicle screw in the pedicle portion of the vertebraand anterior stabilization via the connecting screw, the vertebralstabilization assembly of the present invention provides improvedstabilization about a point central to the vertebral body versus aboutposterior or anterior edges of the vertebra. Thus, the present inventioncentrally distributes the stabilization pressures, tensions, weight, andstress as opposed to focusing the stabilization pressures about theouter edges of the vertebra. The central stabilization promotes improvedstabilization of the vertebrae and improved fusion of the vertebrae.

In yet another aspect, the present invention provides a vertebralstabilization assembly having dual pedicle screws for placement in afirst vertebra including a first pedicle screw, a second pedicle screwand a connecting screw. The first pedicle screw has a shaft providedwith a threaded portion operable for threading engagement of the firstpedicle screw with the first vertebra. The shaft of the first pediclescrew has an engaging portion.

The second pedicle screw has a shaft provided with a threaded portionoperable for threading engagement of the second pedicle screw with thefirst vertebra, the shaft of the second pedicle screw has an engagingportion. The connecting screw has a first end and a shaft, the first endof the connecting screw is adapted to be received by the engagingportion of the first pedicle screw. The shaft of the connecting screw isadapted for connection to the engaging portion of the second pediclescrew.

In one aspect, the engaging portion of the second pedicle screw isdefined as a threaded opening operable for the connecting screw toextend through and further operable to secure a portion of the shaft ofthe connecting screw.

In another aspect, a fixation tool is provided for placement of thefirst and second pedicle screws in the first vertebra so as to align thefirst and second pedicle screws for connection by the connecting screw.The fixation tool includes a first alignment member disposed adjacent asecond alignment member, a third alignment member is offset relative tothe first and second alignment members. The first and second alignmentmembers of the fixation tool provide alignment for positioning the firstand second pedicle screws in the vertebra. The third alignment member ofthe fixation tool aligns the connecting screw for coupling with thefirst and second pedicle screws.

Other objects, features, and advantages of the present invention will beapparent to those skilled in the art from the following detaileddescription when read in conjunction with the accompanying drawings andappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and theadvantages thereof, reference is now made to the following briefdescription, taken in connection with the accompanying drawings anddetailed description, wherein like reference numerals represent likeparts, in which:

FIG. 1 is a perspective view of a vertebral stabilization assemblyillustrated partially in phantom and shown stabilizing an upper andlower vertebra according to one aspect of the present invention;

FIG. 2 is a perspective view of the vertebral stabilization assembly, asshown in FIG. 1, constructive in accordance with the present invention;

FIG. 3 is a side view of a connecting member constructed in accordancewith one aspect of the present invention;

FIG. 3A is a side view of yet another aspect of the connecting member ofthe present invention;

FIG. 3B is a side view of one aspect of a connecting screw shown withthe connecting member attached to the connecting screw by a nut;

FIG. 4 is a side elevational view of a pedicle screw according to oneaspect of the present invention;

FIG. 5 is a top plan view of the pedicle screw, illustrated in FIG. 4,shown posteriorly positioned in a lumbar vertebra in accordance with thepresent invention;

FIG. 6 is a perspective view of a guide member according to one aspectof the present invention for aligning a connecting screw shown inphantom;

FIG. 7 illustrates alignment of the connecting screw utilizing the guidemember for attachment of the connecting screw to the pedicle screwpositioned within the lumbar vertebra, as shown in FIG. 5, according toone aspect of the present invention;

FIG. 8 illustrates a left side posterior positioning of the pediclescrew and alignment of the connecting screw utilizing the guide memberaccording to yet another aspect of the present invention;

FIG. 9 is a top plan view of other aspects of the guide member and thepedicle screw shown connected in accordance with yet another aspect ofthe present invention;

FIG. 10 illustrates alignment of the connecting screw utilizing theguide member, as shown in FIG. 9, for attachment of the connecting screwto the pedicle screw positioned within the lumbar vertebra according toone aspect of the present invention;

FIG. 11 is a perspective view illustrating yet another aspect of theconnection of the pedicle screw with the guide member constructed inaccordance with the present invention;

FIG. 12 is a flow chart illustrating a method for stabilizing vertebraefrom the anterior side of the vertebrae utilizing the vertebralstabilization assembly according to another aspect of the presentinvention;

FIG. 13 is a perspective view illustrating yet another aspect of thepedicle screw provided with a shaft having a reinforced portion;

FIG. 14 is a perspective view of another aspect of the pedicle screwillustrating the shaft with at least a first groove and a flat surfaceon a distal end of the shaft constructed in accordance with the presentinvention;

FIG. 15 is a cross-sectional view of the shaft of the pedicle screwillustrated in FIG. 14 taken along line 15-15 thereof;

FIG. 16 is a perspective view of a cap according to one aspect of thepresent invention for attachment near the distal end of the pediclescrew;

FIG. 17 is a perspective view of one aspect of a tool for connectionnear the distal end of the pedicle screw constructed in accordance withthe present invention; and

FIG. 18 is a perspective view of yet another aspect of the tool for usewith the vertebral stabilization assembly of the present invention shownconnecting to the connecting screw;

FIG. 19 is a top plan view of a bore screw according to one aspect ofthe present invention shown obliquely disposed in the vertebra;

FIG. 20 is a top plan view of an indicator constructed in accordancewith one aspect of the present invention disposed in a bore opening ofthe vertebra;

FIG. 21 is a top plan view of the pedicle screw for anterior placementaccording to yet another aspect of the present invention shown with adistal end of the pedicle screw anchored in the pedicle portion of thevertebra;

FIG. 22 illustrates the guide member of the vertebral stabilizationassembly attaching adjacent a head portion of the anteriorly placedpedicle screw according to one aspect of the present invention;

FIG. 23 is a top plan view of another aspect of the engaging portion ofthe pedicle screw of present invention for attachment to the connectingscrew at various angles;

FIG. 24 is a perspective view of one aspect of the pedicle screw of theprovided with non-continuous threads;

FIG. 25 is a top view of one aspect of the present inventionillustrating placement of dual pedicle screws in the vertebra utilizinga fixation tool;

FIG. 26 is a top plan view of one aspect of dual pedicle screwsinvention illustrated anteriorly placed and connected to the connectingscrew; and

FIG. 27 is a top plan view according to one aspect of the presentinvention illustrating a connecting screw extending across the vertebraand connected to one or dual pedicle screws.

DETAILED DESCRIPTION OF THE INVENTION

It should be understood at the outset that although an exemplaryimplementation of the present invention is illustrated below, thepresent invention may be implemented using any number of techniques,whether currently known or in existence. The present invention should inno way be limited to the exemplary implementations, drawings, andtechniques illustrated below, including the exemplary design andimplementation illustrated and described herein.

FIG. 1 illustrates one aspect of the vertebral stabilization assembly 10constructed in accordance with the present invention. The vertebralstabilization assembly 10 is an innovative device for stabilizing aplurality of vertebrae of the spine. The vertebral stabilizationassembly 10 includes a first pedicle screw 12 and a second pedicle screw14. The first pedicle screw includes a shaft 16 provided with a threadedportion 18. The threaded portion 18 of the shaft 16 is operable forthreading engagement of the first pedicle screw 12 with a first vertebra20. The shaft 16 of the pedicle screw 12 further includes an engagingportion 22.

The second pedicle screw 14 is substantially similar to the firstpedicle screw 12 in that the second pedicle screw 14 includes a shaft 30substantially similar to the shaft 16 of the first pedicle screw 12. Theshaft 16 and 30 of the first and second pedicle screws 12 and 14,respectively, are substantially cylindrical members. The shaft 30 of thesecond pedicle screw 14 is similarly provided with a threaded portion 32similar to the threaded portion 18 provided on the shaft 16 of the firstpedicle screw 12. The threaded portion 32 of the shaft 30 is operablefor threading engagement of the second pedicle screw 14 with a secondvertebra 34. The shaft 30 of the first pedicle screw 14 is provided withan engaging portion 36.

The shafts 16 and 30 of the first and second pedicle screws 12 and 14are of appropriate length to sufficiently anchor the first and secondpedicle screws 12 and 14 in the first and second vertebra 20 and 34,respectively. The threaded portions 18 and 32 of the first and secondpedicle screws 12 and 14 may be threads similar to those on ordinaryscrews and extending a distance from the shafts 16 and 30 sufficient topromote optimum anchoring of the first and second pedicle screws 12 and14 within the first and second vertebra 20 and 34, respectively. Thefirst and second pedicle screws 12 and 14 are constructed of a rigidmaterial such as, but not limited to, steel, metal, or metal alloys,polymeric material, or a variety of other substantially rigid materialsadapted to promote rigid engagement of the first and second pediclescrews 12 and 14 to the first and second vertebra 20 and 34,respectively.

The vertebral stabilization assembly 10 is further provided with a firstconnecting screw 40 and a second connecting screw 42. The first andsecond connecting screws 40 and 42 are substantially cylindrical membersand may be constructed from materials similar to that of the first andsecond pedicle screws 12 and 14, such as, but not limited to, titanium,steel, metal or other metal alloys, substantially rigid polymericmaterial or a variety of other rigid metallic materials adapted andsuitable for these purposes. The first connecting screw has a first end44 adapted to be received by the engaging portion 22 on the shaft 16 ofthe first pedicle screw 12. The second connecting screw 42 has a firstend 46 adapted to be received by the engaging portion 36 of the shaft 30of the first pedicle screw 14.

The vertebral stabilization assembly 10 further includes a connectingmember that has a first end 52 and a second end 54. The first end 52 ofthe connecting member 50 is connected to the first connecting screw 40that is positionable in the first vertebra 20. The second end 54 of theconnecting member 50 is connected to the second connecting screw 42positionable in the second vertebra 34 for stabilization of the firstvertebra 20 and the second vertebra 34. The connecting member 50 may beconstructed from a variety of materials similar to that of the first andsecond pedicle screws 12 and 14 such as, but not limited to, titanium,steel, metal, or other metal alloys, rigid polymeric material, or otherrigid materials suitable for stabilization of the first and secondvertebra 20 and 34 by connection to the first and second connectingscrews 40 and 42.

FIG. 2 illustrates the vertebral stabilization assembly 10,substantially as shown in FIG. 1, with the first and second vertebra 20and 34 removed from the illustration for the purpose of furtherdescribing the present invention. It can be seen that the first andsecond pedicle screws 12 and 14 are provided with a head 60 and 62,respectively. The heads 60 and 62 of the first and second pedicle screws12 and 14 may be configured to receive a tool, such as, but not limitedto, a standard flat or a Phillips-head screw driver, Allen or otherwrench connection, or a variety of male to female or female to maletemporary interconnections for threadingly engaging the first and secondpedicle screws 12 and 14 into the first and second vertebra 20 and 34.

In other embodiments (not shown) the heads 60 and 62 of the first andsecond pedicle screws 12 and 14 may be configured unlike the head of thestandard screw and instead unitarily formed, for example, rectangularlyfrom the shaft 16 and 30 for mating engagement with a unique tooladapted to receive the rectangularly-formed shaft.

It will be appreciated that a variety of constructions andconfigurations of the heads 60 and 62 of the first and second pediclescrews 12 and 14 will readily suggest themselves to one of ordinaryskill in the art and may be provided in numerous configurations suchthat a tool may be attached temporarily to the heads 60 and 62 forimparting a rotation upon the first and second pedicle screws 12 and 14.

In the present illustration, the engaging portion 22 of the shaft 16 canbe more easily seen as adapted to receive the first end 44 of the firstconnecting screw 40. The engaging portion 22 of the shaft 16 is athreaded opening formed in the shaft 16 of the first pedicle screw 12and adapted to receive a threaded first end 44 of the first connectingscrew 40. In this manner the first connecting screw 40 threadinglyengages the engaging portion 22 to achieve a rigid locking connectionbetween the first pedicle screw 12 and the first connecting screw 40.

In other embodiments (not shown) the engaging portion 22 may be atension connection opening in the shaft 16 for receiving and engaging ina tensioning fashion the first end 44 of the first connecting screw 40.In yet other embodiments (not shown) the engaging portion 22 may be alocking assembly adapted to receive the first end 44 of the firstconnecting screw 40 and lock into place upon insertion. The lockingengagement of the engaging portion 22 may be accomplished in a varietyof manners including a keyed design of the engaging portion 22 such thatwhen the first end 44 of the first connecting screw 40 is inserted intothe engaging portion 22 it is locked into place upon rotation of thefirst connecting screw 40.

Yet in other embodiments (not shown), the engaging portion 22 may be amodification to the outer surface of the shaft 16 of the first pediclescrew 12 such that the first end 44 of the first connecting screw 40 maybe adapted to receive the engaging portion 22 of the shaft 16 within anopening in the first end 44 of the first connecting screw 40. In thismanner the locking or tensioning mechanism may be retained by the firstend 44 of the first connecting screw 40 for engaging the firstconnecting screw 40 with the first pedicle screw 12.

A number of other connections including spring, ball, or othertensioning connections, as well as, threading, locking, and other matingconnections for engaging the first end 44 of the first connecting screw40 with the engaging portion 22 of the shaft 16 of the first pediclescrew 12 will readily suggest themselves to one of ordinary skill in theart and are within the spirit and scope of the present invention. Itwill be appreciated that the engaging portion 36 of the shaft 30 of thesecond pedicle screw 14 may be constructed substantially identical tothe engaging portion 22 of the shaft 16 of the first pedicle screw 12.For purposes of brevity no further discussion of the engaging portion 36is deemed necessary to enable one of ordinary skill in the art on thevariety of means for engaging the first and second connecting screw 40and 42 with the first and second pedicle screw 12 and 14 in light of thediscussion regarding the engaging portion 22 of the first pedicle screw12.

The first connecting screw 40 is constructed substantially similar tothe second connecting screw 42 and for this reason, only the firstconnecting screw 40 will be discussed and described for purposes ofbrevity. The first connecting screw 40 is connected to the connectingmember 50 near a second end 64 of the first connecting screw 40. Theconnection of the first connecting screw 40 to the connecting member 50may be accomplished in a variety of manners such as, as shown in thepresent illustration, by providing a threaded portion on the second end64 of the first connecting screw 40.

In this manner, a coupling 70 may be coupled to the second end 64 of thefirst connecting screw 40 and attached using a standard nut threadinglyengaged with the threaded portion 66 of the second end 64 of the firstconnecting screw 40. The coupling portion 70 may be provided with anoffset member 74 adapted to receive a rod 76. The offset member 74thereby tensions the portion of the rod 76 extending through the offsetmember 74 for rigid engagement of the rod 76 to the coupling 70.

The tensioning engagement of the rod 76 by the offset member 74 may beaccomplished by providing a screw (not shown), or othertension-imparting structure, threaded through the offset member 74 andinto contact with the portion of the rod 76 extending through the offsetmember 74. The use of the coupling 70 and the rod 76 is a simple anduseful design, according to one aspect, of the connecting member 50 forstabilization of the first and second vertebrae 20 and 34 via the firstand second connecting screws 40 and 42.

It should be appreciated, however, that the connecting member 50 may beaccomplished utilizing a variety of other structural connections to thefirst and second connecting screws 40 and 42. For example, in oneembodiment (not shown), an opening may extend through the second end 64of the first connecting screw 40. The opening of sufficient diameter toreceive the rod 76 there through the opening in the second end 64 of theconnecting screw 40. A tensioning connection, such as a screw or a nutmay be utilized to tensionally engage the rod thereto the second end 64of the first connecting screw 40. Other configurations of the coupling70 may be utilized for these purposes and are within the spirit andscope of the present invention and will readily suggest themselves toone of ordinary skill in the art.

FIG. 3 illustrates a side view of another aspect of the connectingmember 50 of the vertebral stabilization assembly 10 of the presentinvention. In this aspect the connecting member 50 is a bracket 90having a first opening 92 and a second opening 94. The bracket 90, aswith the various aspects of the connecting member 50, may be constructedfrom a variety of substantially rigid materials such as titanium, steel,metal or metal alloys, rigid polymeric material and other substantiallyrigid materials which may be utilized for these purposes.

The bracket 90 is a substantially flat plate provided with the first andsecond openings extending there through for receiving the first andsecond connecting screws 40 and 42. In this manner, the second end 64 ofthe first connecting screw 40 may be cause to extend through the firstopening 92 of the bracket 90. The nut or other similar device 72 canthen be threadingly engaged about the threaded portion 66 and caused torigidly engage the bracket 90 to the second end 64 of the firstconnecting screw 40. Similarly, the second opening 94 may be adapted toreceive the second connecting screw 42 for attachment thereto.

The symmetrical nature of the vertebral stabilization and assembly 10lends itself to stabilization of a plurality of vertebrae. That is, thefirst and second pedicle screws 12 and 14 are substantially similar, asare the first and second connecting screws 40 and 42. Thus, while only afirst and second pedicle screws 12 and 14 and a first and secondconnecting screws 40 and 42 are shown, the present inventioncontemplates stabilization of two or more vertebrae and is well suitedfor these purposes. In other embodiments (not shown) a third, fourth, ormore pedicle screws may be utilized for engagement of a third, fourth,or more connecting screws for stabilization of a plurality of vertebrae.As such, the connecting member 50, or the bracket 90, shown in FIG. 3,will be provided having appropriate length or with the appropriatenumber of openings to receive each of the connecting screws forstabilizing the desired number of vertebrae.

One advantage of the vertebral stabilization assembly 10 of the presentinvention is that the connecting member fifty, whether utilizing thebracket 90 or the coupling 70 with the rod 76 (see FIG. 2) is adaptedfor connection on the anterior or front side of the vertebrae. Theconnecting member 50 according to the present invention has a lowprofile and thus minimizes the interference with soft tissue within theanterior of the patient.

Another advantage of the present invention is that the first pediclescrew 12 engaging the first connecting screw 40 provides for maximumstabilization in the vertebra 20. As such secure attachment to thevertebra 20 is optimized and greater stabilization can be accomplishedby the innovations provided according to the present invention.Furthermore, the first pedicle screw 12 so connected to the firstconnecting screw 40 has the effect of inhibiting the first pedicle screw12 from backing out of the vertebra 20, as well as preventing the firstconnecting screw 40 from backing out of the vertebra 20 as well.

FIG. 3A illustrates another aspect of the connecting member 50 that issimilar to the bracket 90, illustrated in FIG. 3. In this aspect thebracket 90 is provided with a single opening 96 having a first end 97and a second end 98 extending through the bracket 90. The opening 96near the first and second ends 97 and 98 are provided with a pluralityof notches 99 adapted for securely receiving a portion of a screw, suchas the second end 64 of the first connecting screw 40.

The bracket 90 is useful where the first connecting screw 40 and thesecond connecting screw 42 are not substantially aligned vertically.Thus, the notches 99 are provided so that the first and secondconnecting screws 40 and 42 may be connected to the bracket 90 atvarious notches 99 on the first and second ends 97 and 98, respectively,of the bracket 90 while maintaining the bracket 90 disposed in asubstantially vertical manner while the first and second connectingscrews 40 and 42 may not be substantially vertical with respect to oneanother.

FIG. 3B illustrates another aspect of the first connecting screw 40shown attached to the connecting member 50, such as the bracket 90,using a capped bolt 104. It can be seen that the second end 64 of thefirst connecting screw 40 is provided with a notch 106 such that thebracket 90 is flush against the notch 106 of the first connecting screw40 for secure attachment thereto. A capped bolt 104 or other low-profileconnectors may be utilized advantageously so as to minimize theinterference and contact of the vertebral stabilization assembly 10 ofthe present invention with any of the soft tissue of the patient.

FIG. 4 illustrates another aspect of the present invention of thepedicle screw, such as the pedicle screw 12, for securing a connectingscrew, such as the first connecting screw 40, of the vertebralstabilization assembly 10 of the present invention. In this aspect thepedicle screw 12, as well as having the shaft 16 having the threadedportion 18 and the engaging portion 22, as previously discussed, furtherincludes a coupling portion 100 provided on the shaft 16.

The coupling portion 100 is adapted to connect a guide member (whichwill be discussed in greater detail with reference to FIG. 6) of thevertebral stabilization assembly. In one aspect the coupling portion 100may be a threaded portion on the outer surface of the shaft 16 near thedistal end 102 of the shaft 16. The guide member may be threadinglyconnected to the coupling portion 100 about the distal end 102 of theshaft 16. In other embodiments, however, the coupling portion may be anopening provided in the distal end 102 of the shaft 16 such that aportion of the guide member may be threadingly received within theopening in the distal end 102 of the shaft 16 for threading engagementtherewith the coupling portion 100.

As previously mentioned, the engaging portion 22 of shaft 16 is operableto receive the first connecting screw 40. The engaging portion 22 in oneembodiment may be provided as an opening on the shaft 16 extendingcompletely through the shaft 16. The purpose of the engaging portion 22,as previously discussed, is to provide stabilizing engagement of thefirst connecting screw 40 with the first pedicle screw 12. As previouslydiscussed, this rigid engagement may be provided in a variety ofmanners, such as, but not limited to, a locking engagement, a threadingengagement, a tensioning or other rigid coupling connection of the firstconnecting screw 40 with the first pedicle screw 12 about the engagingportion 22.

Referring also to FIG. 5 a top view of a vertebra 118, such as a lumbarvertebra, shown with the first pedicle screw 12 set therein. Oneadvantage of the present invention is that the first pedicle screw 12may be placed through a pedicle 120 on a posterior side 122 of thevertebra 118.

Posterior placement through the pedicle 120 of the vertebra 118 providesoptimum stability and anchoring of the first pedicle screw 12 bythreading engagement through the most rigid portions of the vertebra118. Significant problems arise when the first pedicle screw 12 is notwell anchored within the vertebra 118 and alternate placement is thenrequired. Furthermore, stabile anchoring is critical to reduce thelikelihood that the first pedicle screw 12 will back out, or comebackwards out of its placement, of the vertebra 118. The illustratedplacement of first pedicle screw 12 advantageously overcomes thedisadvantages associated with unstable attachment common with anteriorvertebral stabilization systems.

As previously mentioned, the connecting member 50 is positionable on theanterior side 124 of the vertebra 118. Thus, the vertebral stabilizationassembly 10 of the present invention achieves the advantages of anteriorvertebral stabilization, since the connecting member is positioned onthe anterior side 124 of the vertebra 118, while simultaneouslyachieving the stability associated with posterior procedures.

The first pedicle screw 12 may be placed in the vertebra 118,substantially as shown, percutaneously or through the skin requiringonly a small incision, and avoiding the disadvantages associated withlarge, invasive posterior procedures which require significantinterference and dissection of adjacent muscles.

In yet another aspect of the present invention the pedicle screw 12 maybe provided with a cannulated shaft 16 such that a passageway 110extends through the shaft 16 from the head 60 to the distal end 102thereof the shaft 16. By utilizing the passageway 110 extending throughthe shaft 16 of the first pedicle screw 12, a tool (not shown) such as atap or drill bit may be placed through this cannulated portion of theshaft 16 such that the tool or drill bit enters near the head 60 of thefirst pedicle screw 12. The tool is then extended through the passageway110 towards the distal end 102.

The tool may then be utilized to drill through to the anterior side 124of the vertebra 118 for location of the distal end 102 of the pediclescrew 12 from the anterior side 124 of the vertebra 118. Since only asmall distance must be drilled, there is minimal risk to soft tissue orblood vessels. Furthermore, once the tool penetrates the anterior side124 of the vertebra 118, the surgeon should be able to sense the reducedresistance and friction on the tool. Furthermore, the tool may beprovided with stops or a drill bit may be cannulated to preventextension of the drill beyond the anterior side 124 of the vertebra 118.

In the present embodiment right side 126 placement of the first pediclescrew 12 is preferable to avoid soft tissue injuries to the patient'santerior caused by penetration of the drill bit through the anteriorside 124 of the vertebra 118 via the passageway 110 of the first pediclescrew 12. Anatomically, fragile soft tissue and blood vessels arepositioned adjacent the right side 126 on the anterior side 124 of thevertebra 118. By using any number of surgical retraction techniques,these blood vessels may be held toward the right side 126 of theanterior side 124 of the vertebra 118. As such, the right side 126placement of the first pedicle screw 12 represents the most efficient,as well as safest, placement for utilizing the first pedicle screw 12 inaccordance with the present invention. In some instances, however, leftside 128 placement of the first pedicle screw 12 in the vertebra 118will be necessary. Left side 128 placement of the first pedicle screw 12will be discussed in greater detail with reference to FIG. 8.

FIG. 6 illustrates yet another aspect of the present invention of aguide member 150. The guide member 150 includes a coupling portion 152an offset member 154 and an alignment member 156. The coupling portion152 is operable to couple with the coupling portion 100 of the firstpedicle screw 12 (see FIG. 4). The offset member 154 is connected to thecoupling portion 152. The offset member 154 extends from the couplingportion 152 relative to the connection of the coupling portion 152 tothe coupling portion 100 of the first pedicle screw 12. The alignmentmember 156 is connected to the offset member 154. The alignment member156 is operable for alignment of the connecting screw, such as the firstconnecting screw 40, with a portion of the first pedicle screw 12, suchas the engaging portion 22.

The guide member 150 may be constructed from a variety of materials suchas, but not limited to, titanium, steel, metal or other metal alloys, asubstantially rigid polymeric material, aluminum or other substantiallyrigid materials sufficient for these purposes. The coupling portion 152is provided with a first end 160 and a second end 162. The first end 160of the coupling portion 152 may be threaded for threading engagement tothe coupling portion 100 of the first pedicle screw 12.

It should be appreciated, however, that a number of connecting methodsmay be utilized to accomplish the connection of the first end 160 of thecoupling portion 152 to the coupling portion 100 of the first pediclescrew 12. For example, the first end 160 may be shaped so as to besubstantially rectangular or other geometric shape about a portion ofthe first end 160 such that a similarly geometrically configured openingin the coupling portion 100 in the distal end 102 of the first pediclescrew 12 is adapted to receive the first end 160 of the coupling portion152. Other locking or tensioning engagements of the first end 160 of thecoupling portion 152 to the coupling portion 100 of the first pediclescrew 12, as well as a variety of other methods for achieving thisattachment, will readily suggest themselves to one of ordinary skill inthe art and are within the spirit and scope of the present invention.

The second end 162 of the coupling portion 152 is attached to the offsetmember 154. The attachment of the coupling portion 152 to the offsetmember 154 may be of a connecting, such as threading or tensioning orlocking connection, or may be accomplished by a welded or bondedconnection of the second end 162 of the coupling portion 152 to theoffset member 154. Although welding or bonding engagements of variouscomponents of the vertebral stabilization assembly 10 of the presentinvention are preferable, it should be appreciated that bonding or othergluing or tacking materials may be used for this connection andsatisfactory for these purposes.

The offset member 154 is shown as a substantially arcuate memberextending from the second end 162 of the coupling portion 152 to thealignment member 156. However, in other embodiments, one of which isdescribed hereinafter, the alignment member 156 may be comprised of anumber of foldable or extendable or hinging segments to promote usewithin the confinements of the patient's anterior. While the offsetmember 154 is shown as a substantially rigid arcuate member, a number ofother configurations of the offset member 154, such as a substantiallystraight member, or a stair-stepped member, as well as the offset member154 being comprised of several connectable or extendable members arecontemplated according to other aspects (not shown) of the presentinvention.

A number of configurations of the offset member 154, such as formationof a portion of the offset member 154 unitarily with the couplingportion 152 and formation of a remaining portion of the offset member154 unitarily formed with the alignment member 156 may also be utilizedfor these purposes. Although the offset member 154 is shown in thepreferred aspect, a variety of configurations of the offset member 154will readily suggest themselves to one of ordinary skill in the art forpositioning the alignment member 156 relative to a portion of the firstpedicle screw 12 when the coupling portion 152 of the guide member 150is connected to the coupling portion 100 of the first pedicle screw 12and are within the spirit and scope of the present invention and willnot be discussed in further detail for the purposes of brevity.

The alignment member 156 is rigidly connected to the offset member 154by welding or bonding or other similar means. However, attachment of thealignment member 156 to the offset member 154 may be accomplished by athreading, locking or tensioning engagement and is satisfactory forthese purposes. The alignment member 156 is a substantially tubularmember having a first end 164 and a second end 166 and an opening 168extending through from the first end 164 to the second end 166.

The alignment member 156 is provided such that the opening 168 is of asufficient diameter to receive a drilling device 170, shown in phantom,through the opening 168 for alignment with the engaging portion 22 onthe shaft 16 of the first pedicle screw 12. The drilling device 170 maybe the a bit of a drill or other devices operative to drill an openinginto vertebral bone. Thus, the alignment member 156 receives thedrilling device 170 that drills an opening properly aligned forattachment of the first connecting screw 40 to the first pedicle screw12. Thus, the guide member 150 is advantageously provided for creatingan opening aligned with the engaging portion 22 of the first pediclescrew 12.

It should be appreciated that while the alignment member 156 of thepresent aspect is illustrated as a substantially tubular member havingan opening 168, other embodiments the alignment member 156 may not be acompletely tubular, and instead, be provided as a guide or positioningmember for alignment of the first connecting screw 40 with the engagingportion 22 of the first pedicle screw 12.

Numerous configurations for aligning the first connecting screw 40 withthe engaging portion 22 of the first pedicle screw 12 may be utilizedfor these purposes and will readily suggest themselves to one ofordinary skill in the art and are within the spirit and scope of thepresent invention and will not be discussed further for purposes ofbrevity.

FIG. 7 illustrates a top view of the vertebra 118 shown with the firstpedicle screw 12 positioned therein with the guide member 150 shownattached to the first pedicle screw 12. In this view, it can be seenthat the guide member 150 is a useful tool for placement of the firstconnecting screw 40 for attachment to the engaging portion 22 of thefirst pedicle screw 12. It will be appreciated that, procedurally, thefirst pedicle screw 12 has been percutaneously placed through theposterior side 122 of the vertebra 118. Thereafter the tool, such as thedrill, as previously discussed, is caused to drill through the anteriorside 124 of the vertebra 118 thus locating the position of the couplingportion 100 on the distal end 102 of the first pedicle screw 12.

At this point, the guide member 150 may be positioned such that thecoupling portion 152 extends through the drilled opening on the anteriorside 124 of the vertebra 118. The coupling portion 152 of the guidemember 150 is then connected to the coupling portion 100 of the firstpedicle screw 12. An innovative aspect of the pedicle screw 12 is thatthe coupling portion 100 on the distal end 102 of the first pediclescrew 12 is associated with the engaging portion 22 on the shaft 16 ofthe first pedicle screw 12. The association of the coupling portion 100and engaging portion 22 of the first pedicle screw 12 is a significantadvantage of the first pedicle screw 12 according to the presentinvention. That is, this association allows for the guide member 150 tobe configured relative to this association. Thus, the coupling portion152 of the guide member 150, when coupled to the first pedicle screw 12,aligns the alignment member 156 with the engaging portion 22 on theshaft 16 of the first pedicle screw 12. Utilizing the guide member 150,several methods exist for aligning and securing the first connectingscrew 40 to the first pedicle screw 12. It may be preferable to utilizethe drilling device 170 to create an opening in the anterior side 124 ofthe vertebra 118. Thereafter, the guide member 150 may be removed andthe first connecting screw 40 disposed through the opening drilled inthe vertebra 118 and connected to the first pedicle screw 12.

In some instances, it may be beneficial for the alignment member 156 tobe adapted to receive the first connecting screw 40 positioned to extendthrough the opening 168 of the alignment member 156. The firstconnecting screw 40 may then be drilled or threaded directly into theleft side 128 of the anterior side 124 of the vertebra 118. Whether anopening is first drilled or the first connecting screw 40 is directlydrilled into the vertebra 118, the unique configuration of the guidemember 150 relative to the first pedicle screw 12 insures that the firstconnecting screw 40 will be properly aligned so as to locate theengaging portion 22 of the first pedicle screw 12 for engagingattachment thereto.

Thus, another advantage of the guide member 150 of the present inventionis that the coupling portion 152 of the guide member 150 is operable tocouple with the coupling portion 100 of the first pedicle screw 12 suchthat the offset member 154 extends in a predetermined direction relativeto the coupling of the coupling portion 152 of the guide member 150 tothe coupling portion 100 of the first pedicle screw 12. The offsetmember 154 of the guide member 150 is positionable relative to thecoupling of the coupling portion 152 of the guide member 150 with thecoupling portion 100 of the first pedicle screw 12.

It will be appreciated that the connection of the coupling portion 152of the guide member 150 to the coupling portion 100 of the first pediclescrew 12 must be a locking or fitted type connection such that theoffset member 154 properly extends in the proper direction to positionthe alignment member 156 for alignment with the engaging portion 22 ofthe first pedicle screw 12. Achieving the accuracy necessary to locatethe engaging portion 22 of the first pedicle screw 12, which will not bevisible since the first pedicle screw 12 will be embedded within thevertebra 118, is preferably accomplished through the accurate couplingconnection of the coupling portion 152 of the guide member 150 to thecoupling portion 100 of the first pedicle screw 12.

It should be understood, however, that a number of other methods oflocating the engaging portion 22 of the first pedicle screw 12 foralignment with the first connecting screw 40 may be utilized. Forexample, providing indicia or markings on the head 60 of the firstpedicle screw 12 indicating the relative position of the engagingportion 22 of the first pedicle screw 12. The coupling portion 152 mayfurther include an extension (not shown) extendable through thepassageway 110 of the shaft 16 of the first pedicle screw 12. Theextension of the coupling portion 152 of the guide member 150 similarlyprovided with indicia, markings, or an alignment with the indiciaprovided on the head 60 of the first pedicle screw 12. In this manner,when the indicia are aligned, so is the alignment member 156 alignedwith the engaging portion 22 on the first pedicle screw 12.

A variety of other methods for obtaining this positioning and alignmentfor connecting the first connecting screw 40 to the first pedicle screw12 will readily suggest themselves to one of ordinary skill in the artand are within the spirit and scope of the present invention and willnot be discussed for purposes of brevity.

FIG. 8 illustrates an alternative left side 128 placement of the firstpedicle screw 12 in the vertebra 118. Procedurally, numerous methods maybe utilized to determine whether the first pedicle screw 12 issatisfactorily stabilized within the vertebra 118, including electricalstimulation to test for a desired threshold. In certain circumstances,such as when the right side 126 placement of the first pedicle screw 12is ineffective to achieve the desired or required stability, left side128 placement of the first pedicle screw 12 may be necessary. In thisinstance, the present invention may be utilized in substantially thesame manner for left side 128 placement.

The significant difference between the first pedicle screw 12 utilizedfor right side 126 placement, as opposed to left side 128 placement, isan angle 176 of the engaging portion 22 of the first pedicle screw 12relative to an axis extending centrally through the shaft 16, such asthe passageway 110 of the first pedicle screw 12. It can be seen thatthe angle 176 of the engaging portion 22 of the first pedicle screw 12necessary for placement of the first connecting screw 40 about the leftside 128 of the anterior side 124 of the vertebra 118 variesconsiderably depending upon whether the first pedicle screw 12 isconnected from the left side 128 or the right side 126 of the vertebra118. For this reason, a unique first pedicle screw 12 and guide member150 will be constructed for the left side 128 versus right side 126placement, such that the guide member 150, when connected to the firstpedicle screw 12, properly aligns the first connecting screw 40 basedupon which vertebral placement, and corresponding first pedicle screw 12is utilized.

FIG. 9 illustrates another aspect of the first pedicle screw 12 as wellas another aspect of the guide member 150. The vertebra 118 is shownhaving a midline 178 extending from the anterior side 124 to theposterior side 122 of the vertebra 118. The coupling portion 152 of theguide member 150 is shown connected to the first pedicle screw 12 on theleft side 128 of the vertebra 118 adjacent the midline 178. Aspreviously discussed, placement of the first pedicle screw 12 on theleft 128 anterior side 124 of the vertebra 118 may be preferable.

In this aspect the guide member 150 is shown having a substantiallynon-arcuate offset member 154 such that the alignment member 156 extendsangularly therefrom the offset member 154. The coupling portion 152 isshown as a substantially tubular member having a channel 180 extendingthrough the coupling portion 152. The coupling portion 152 is providedwith a recess 182 extending into the channel 180 near the first end 160of the coupling portion 152. Furthermore, in this aspect, the first end160 of the coupling portion 152 is adapted to matingly receive the firstpedicle screw 12 near the distal end 102 thereof. As previouslydiscussed, the first pedicle screw 12 is provided with a couplingportion 100 provided, in this aspect, as an opening in the distal end102 of the first pedicle screw 12.

A locking screw 184 may be extended through the channel 180 from thesecond end 162 toward the first end 160 of the coupling portion 152. Thelocking screw 184 is provided with a head 186 having a larger diameterthan that of a shaft 188 portion of the locking screw 184. The first end160 of the coupling portion 152 is matingly connectable to the distalend 102 of the first pedicle screw 12. The locking screw 184 ispositioned through the channel 180 until the shaft 188 portion of thelocking screw 184 couples with the coupling portion 100 of the firstpedicle screw 12.

A tool (not shown) having any standard screw driver or hex,octagonal-type or other connection, for example, may be extended downthe channel 180 and used to connect the locking screw 184 to thecoupling portion 100 of the first pedicle screw 12. The locking screw184 may be threadingly screwed into engagement with the first pediclescrew 12 or connected in other manners which are well known and willreadily suggest themselves to one of ordinary skill in the art.

In this manner, the head 186 of the locking screw 184 engages the recess182 within the channel 180 of the coupling portion 152 thereby engagingthe coupling portion 152 to the first pedicle screw 12. It will beappreciated that the locking screw 184, the coupling portion 152 and theguide member 150 may be provided with indicia or markings to indicatelocking engagement and alignment with both the first pedicle screw 12and the vertebra 118 since it is critical that the locking screw 184couple the coupling portion 152 to the first pedicle screw 12 at aparticular position relative to the vertebra 118. The indicia ormarkings may include cross-hair lines, a single line or mark, an arrow,or other markings indicating a rotational position desired for achievingthis connection and location.

Such accurate positioning may be accomplished based on the threads ofthe shaft 188 of the locking screw 184 corresponding to threadedopenings within the coupling portion 100 of the first pedicle screw 12.A variety of different structural attachments for obtaining this lockingconnection for alignment of the guide member 150 with the first pediclescrew 12 such that the alignment member 156 is substantially alignedwith the engaging portion 22 on the shaft 16 of the first pedicle screw12 may be utilized and are within the spirit and scope of the presentinvention and will readily suggest themselves to one of ordinary skillin the art.

FIG. 10 illustrates the first pedicle screw 12 placed from the rightside 126 on the posterior side 122 of the vertebra 118. It will beappreciated that the exact placement and size of the first pedicle screw12 relative to the vertebra 118, as shown and disclosed, herein may beenlarged or reduced proportionately depending upon the characteristicsof the vertebra 118 and the goals of the vertebral stabilizationassembly 10. However, the first pedicle screw 12 is preferably securedin the pedicle portion of the vertebra 118 such that the distal end 102of the first pedicle screw 12 is coupleable to the guide member 150 onthe left side 128 on the anterior side 124 adjacent the midline 178 ofthe vertebra 118.

In some aspects, the guide member 150 may be provided with a rotationalcoupling 190 such as a recess or opening in the offset member 154 of theguide member 150. The rotational coupling 190 may be adapted as anopening to receive a tool or device for obtaining leverage on the guidemember 150 for rotation of the guide member 150. It will be appreciatedthat while the first pedicle screw 12 may be provided with indicia orother markings on the head 60 of the first pedicle screw 12 fordetermining the location and disposition of the engaging portion 22 ofthe first pedicle screw 12, a surgeon may have difficulty determiningfrom the posterior side 122 of the vertebra 118 the optimum location forplacement of the connecting screw, such as the first connecting screw40.

Once the patient has been rotated and the guide member 150 connected tothe first pedicle screw 12 on the anterior side 124 of the vertebra 118,only then will the surgeon be able to determine the preferable placementof the first connecting screw 40 relative to the body of the vertebra118. In the event the first pedicle screw 12 is not aligned preferablyfor the first connecting screw 40, by use of the rotational coupling190, such as with a tool connected thereto, the surgeon may rotate theguide member 150 and the first pedicle screw 12 rigidly connectedthereto, via the locking screw 184, to obtain the optimum placement ofthe first connecting screw 40 into a desired point in the body of thevertebra 118. In other embodiments, the guide member 150 may not includethe rotational coupling 190 and, as such, this rotational alignment maybe achieved by grasping and rotating the offset member 154 or otherportions of the guide member 150.

Once this optimum positioning has been obtained by rotation using therotational coupling 190 the tool coupled to the rotational coupling 190may be removed and a drill or other tool may be utilized and aligned viathe alignment member 156 for drilling an opening into the body of thevertebra 118 at the desired location. Thereafter, the locking screw 184and a guide member 150 may be removed for connection of the firstconnecting screw 40 to the engaging portion 22 of the first pediclescrew 12.

It will be appreciated that the locking screw 184 may be connected in avariety of manners to the coupling portion 152 of the guide member 150to obtain a corresponding rotation of the guide member 150 with thefirst pedicle screw 12 for these rotational purposes which will readilysuggest themselves to one of ordinary skill in the art and are withinthe spirit and scope of the present invention.

FIG. 11 illustrates another aspect of the connection of the firstpedicle screw 12 to the coupling portion 152 of the guide member 150. Aspreviously discussed above, a variety of methods exist for connectingthe coupling portion 152 with the coupling portion 100 of the firstpedicle screw 12. In the present aspect illustrated in FIG. 11, thecoupling portion 100 of the first pedicle screw 12 is a substantiallyrectangular member extending therefrom the shaft 16 of the first pediclescrew 12.

The coupling portion 152 of the guide member 150, in the present aspect,is provided with a substantially rectangular opening 196 in the firstend 160 of the coupling portion 152. The substantially rectangularopening 196 is sized to matingly receive the rectangular couplingportion 100 to achieve a fitted coupling there between. In this aspect,the coupling portion 100 may be provided with a threaded opening 198 onthe distal end 102 of the first pedicle screw 12. In this manner, thechannel 180 extending there through the coupling portion 152 may beprovided to guide a connecting member, such as the locking screw 184 orother engaging structure, to be threadingly received by the threadedopening 198 in the distal end 102 of the first pedicle screw 12.

In this manner, the combination of the locking mechanism, such as thelocking screw 184, as well as the rectangular configuration of thecoupling portion 100 of the first pedicle screw 12 with thesubstantially rectangular opening 196 in the first end 160 of thecoupling portion 152 promotes an accurately engaged connection of theguide member 150 with the first pedicle screw 12. It should beappreciated that in other aspects the threaded opening 198 and thechannel 180 may be eliminated and only the mating connection of therectangular coupling portion 100 of the first pedicle screw 12 with thesubstantially rectangular opening 196 of the coupling portion 152 willbe sufficient for this connection.

It will be appreciated that the configuration illustrated in the currentaspect promotes a sufficient engagement of the guide member 150 to thefirst pedicle screw 12 to achieve engaging rotation of the first pediclescrew 12 by the guide member 150 when such adjustment for alignmentpurposes of the first pedicle screw 12 is desirous. It should beappreciated that while the coupling portion 100 of the current aspect isshown as substantially rectangular in configuration as is thesubstantially rectangular opening 196 of the coupling portion 152 of theguide member 150, a variety of other configurations such as, but notlimited to, triangular configurations, will readily suggest themselvesto one of ordinary skill in the art and are within the spirit and scopeof the present invention, as are a variety of other coupling connectionsbetween the coupling portion 152 and the first pedicle screw 12 whichmay be utilized to achieve these purposes.

FIG. 12 is a flow chart illustrating a method 200 for stabilizing anupper and lower vertebra 118A and 118B, substantially similar to thevertebra 118 illustrated in FIGS. 5 and 7, from an anterior side 124 ofthe vertebra 118A and 118B using the vertebral stabilization assembly 10in accordance with the present invention. The method includes, at ablock 202, inserting the first pedicle screw 12 into the lower vertebra118B through the pedicle 120 and into the body of the lower vertebra118B from a posterior side 122 of the lower vertebra 118B. The firstpedicle screw, as previously described above, includes the shaft 16provided with the threaded portion 18 operable to threadingly engage thelower vertebra 118B. The shaft 16 of the first pedicle screw 12 isprovided with the engaging portion 22 that is operable to receive thefirst connecting screw 40. The shaft 16 of the first pedicle screw 12further has the coupling portion 100 that is operable to couple with theguide member 150.

The method further includes, at a block 204, inserting a second pediclescrew 14 into the upper vertebra 118A through the pedicle 120 andvertebral body of the upper vertebra 118A from the posterior side 122 ofthe upper vertebra 118A. The second pedicle screw 14 including the shaft30 provided with the threaded portion 32 operable to threadingly engagethe upper vertebra 118A. The shaft 30 of the second pedicle screw 14provided with an engaging portion 36 operable to receive the secondconnecting screw 42. The shaft 30 of the second pedicle screw 14 havinga coupling portion 100, substantially similar to the coupling portion100 of the first pedicle screw 12, to couple with the guide member 150.

The first and second pedicle screws 12 and 14 are preferably placed onthe posterior side 122 on the right side 126 of the upper and lowervertebra 118A and 118B, respectively. It will be appreciated that in oneaspect the present invention may be utilized preferably with respect tothe lumbar vertebra, while in other embodiments the present inventionmay be preferably utilized with regard to the thoracic vertebra.

At a block 206, the method includes locating the coupling portion 100 ofthe shaft 16 of the first pedicle screw 12 from the anterior side 124 ofthe lower vertebra 118B. As previously discussed, in one aspect thepedicle screw 12 of the present invention may be provided with thecannulated shaft 16 having the passageway 110 extending through theshaft 16 of the first pedicle screw 12. In this aspect a tool, such as adrill operable to drill through a portion of the lower vertebra 118B,may be extended through the passageway 110 of the shaft 16 of the firstpedicle screw 12. The tool may be used to drill through a portion of thelower vertebra 118B such that the tool extends partially through theanterior side 124 at the lower vertebra 118B. Similarly, the secondpedicle screw 14 may be similarly provided with the passageway 110 forpassing the tool there through to drill through a portion of the uppervertebra 118A such that the drill extends at least partially through theanterior side 124 of the upper vertebra 118A.

At a block 208 the method includes coupling the guide member 150 to thecoupling portion 100 of the shaft 16 of the first pedicle screw 12 fromthe anterior side 124 of the lower vertebra 118B. In one aspect thecoupling of the guide member may be more readily accomplished after anopening has been drilled through to the anterior side 124 of the lowervertebra 118B. The method further includes, at a block 210, insertingthe lower connecting screw, such as the first connecting screw 40,through the anterior side 124 of the lower vertebra 118B using the guidemember 150. As previously discussed, the guide member is a useful toolfor aligning the alignment member 156 of the guide member 150 andcorrespondingly the first connecting screw 40 with the engaging portion22 of the first pedicle screw 12.

The method further provides, at a block 212, locating the couplingportion 100 of the shaft 30 of the second pedicle screw 14 from theanterior side 124 of the upper vertebra 118A. The method furtherprovides, at a block 214, for coupling the guide member 150 to thecoupling portion 100 of the shaft 30 of the second pedicle screw 16 fromthe anterior side 124 of the upper vertebra 118A.

At a block 216, the method includes inserting an upper connecting screw,such as the second connecting screw 42 through the anterior side 124 ofthe upper vertebra 118A utilizing the guide member 150 for properalignment. The method also provides, at a block 218, for connecting theupper and lower connecting screws, such as the first and secondconnecting screws 40 and 42, to the connecting member 50 forstabilization of the upper and lower vertebra 118A and 118B.

FIG. 13 illustrates another aspect of the first pedicle screw 12 havinga reinforced portion 230 provided on the shaft 16. The reinforcedportion 230 of the shaft 16 provides additional structural stability forconnection of the connecting screw, such as the first connecting screw40, to the engaging portion 22 to ensure a rigid and stable connectionof the first connecting screw 40 to the first pedicle screw 12. Thereinforced portion 230 is shown having a diameter 232 that is greaterthan a diameter 234 of a first threaded portion 236 of the shaft 16. Inthis manner, it is readily apparent that the reinforced portion 230having a greater diameter 232 will provide additional structuralstability and support for connection of the first connecting screw 40with respect to the smaller diameter 234 of the first threaded portion236 of the shaft 16. The first threaded portion 236 of the shaft 16 isprovided with a plurality of threads 238 connected to and extending fromthe shaft 16 of the first pedicle screw 12. It can be seen that thediameter 232 of the reinforced portion 230 is about equal to a diameter240 measured from an outermost edge of the plurality of threads 238 ofthe first threaded portion 236.

As the first pedicle screw 12 is threadingly engaged into the pedicleportion of the vertebra, such as the first vertebra 20, the firstthreaded portion 236 will threadingly engage and retain the firstpedicle screw 12 within the first vertebra 20. In the present embodimentthe reinforced portion 230 is not provided with threads, however, inother embodiments the reinforced portion may be provided with threadssimilar to the plurality of threads 238 or threads extending less farfrom the reinforced portion 230 than the plurality of threads 238 extendfrom the first threaded portion 236 of the shaft 16. In one aspect, thediameter 232 of the reinforced portion 230 is about 6.5 millimeters.However, in other embodiments the diameter 232 of the reinforced portion230 may be greater or less than 6.5 millimeters as may be necessary toproperly engage the shaft 16 of the first pedicle screw 12 in the firstvertebra 20.

The shaft 16 of the first pedicle screw 12 is further provided with asecond threaded portion 242 having a plurality of threads 244 forengaging the first vertebra 20. In the present aspect, the diameter 232of the reinforced portion 230 is less than the diameter 246 measuredfrom an outermost edge of the plurality of threads 244 provided on thesecond threaded portion 242. As the first pedicle screw 12, of thepresent aspect, is engaged into the first vertebra 20, the firstthreaded portion 236 will threadingly engage the pedicle portion andthereafter an interior vertebral body portion of the first vertebra 20.As the reinforced portion 230 of the first pedicle screw 12 followsbehind the first threaded portion 236, the reinforced portion 230 mayhave the affect of smoothing the threading engagement within thevertebral body. For this reason, it may be advantageous to provide theplurality of threads 244 having a greater diameter 246 for providingadditional threading engagement of the first pedicle screw. In otheraspects (not shown) frictional engaging surface structure, such as smallor low profile threads, may be provided on the reinforced portion 230for frictionally engaging the inner vertebral body at the first vertebra20.

In the present aspect, the diameter 246 of the plurality of threads 244may be about 7.0 millimeters to achieve additional threading engagementof the second threaded portion 242 of the shaft 16 for stable engagementof the first pedicle screw 12 within the first vertebra 20. It will beappreciated, however, that in other aspects (not shown) the diameter 246of the plurality of threads 244 may be of larger or smaller diameter ormay be of a similar or smaller diameter than the diameter 232 of thereinforced portion 230 and be adequate for these purposes. Furthermore,in other aspects (not shown) the diameter 234 of the first threadedportion 236 of the shaft 16 may be the same or larger diameter than thatof the diameter 232 of the reinforced portion 230. The reinforcedportion 230 of the shaft 16 provides significant additional structuralstability for connection of the first connecting screw 40 to the firstpedicle screw 12 via the engaging portion 22. While the length of thereinforced portion 230 relative to the length of the entire shaft 16 ofthe first pedicle screw 12 is shown in relative proportion according tothe present aspect, the reinforced portion 230, according to otheraspects (not shown), may be of significantly greater length and diameteror having a smaller length and diameter relative to the shaft 16 of thefirst pedicle screw 12 and are within the spirit and scope of thepresent invention as disclosed and described herein.

FIG. 14 illustrates a perspective view of another aspect of the pediclescrew 12 wherein the shaft 16 is provided with at least a first groove250 extending a distance along the shaft 16 of the first pedicle screw12. In the present aspect, a plurality of grooves 250 are shown adjacenta plurality of raised threaded portions 252. The raised threadedportions 252 are provided for threadingly engaging the first vertebra 20for securing the first pedicle screw 12 to the first vertebra 20. Theone or more grooves 250 are provided for engaging the first pediclescrew 12 by a tool which will be discussed in greater detail hereinafterwith respect to FIGS. 17 and 18. In certain circumstances it may beuseful or necessary to rigidly retain the first pedicle screw 12 fromthe anterior side of the first vertebra 20, such as when connecting thefirst connecting screw 40 to the first pedicle screw 12. The one or moregrooves 250 provided on the shaft 16 promotes engagement of the firstpedicle screw 12 by a tool near the distal end 102 of the shaft 16.

FIG. 15 illustrates a cross section of the first pedicle screw 12illustrated in FIG. 14 taken along a line 15-15 thereof. In this view,the one or more grooves 250 provided on the shaft 16 of the firstpedicle screw 12 can be seen with respect to their relationship to theraised threaded portions 252. This configuration is useful for promotingengagement of a tool for connecting near the distal end 102 of the firstpedicle screw 12. Although the grooves 250 are shown as generallyrounded in configuration extending a distance along the length of theshaft 16 it will be appreciated that in other embodiments (not shown)the grooves 250 may be angular, such as rectangular or triangular inconfiguration, and having a wider or narrower width 254 which are withinthe spirit and scope of the present invention as disclosed and describedherein.

In this view, it can be seen that a number of grooves 250 such as two orfour grooves 250 may promote improved engagement by a tool of the firstpedicle screw 12 near the distal end 102, however, any number of grooves250 may be utilized and are within the spirit and scope of the presentinvention.

It will be appreciated that the configuration of the first pedicle screw12 illustrated having one or more grooves 250 extending a distance alongthe length of the shaft 16 may also be utilized with respect to theconfiguration of the first and second connecting screws 40 and 42. Inthis manner, a tool may be utilized to connect to the second end 64 ofthe first connecting screw 40 for inserting the first connecting screw40 into the engaging portion 22 of the first pedicle screw 12, as wellas for removal of the first connecting screw 40 from the engagingportion 22 of the first pedicle screw 12.

From time to time it may be necessary to remove portions of thevertebral stabilization assembly 10 of the present invention from thepatient and it will become necessary for the first connecting screw 40and the first pedicle screw 12 to be configured so as to be easilyremovable. It will be appreciated that metal tightly connectedfrequently galls or becomes frozen. In this manner, configuration of thefirst pedicle screw 12 and the first connecting screw 40 having, forexample, grooves 250 and other similar configurations, as previouslydiscussed, and utilization of a tool adapted to engage the grooves 250along the shaft 16 of the first pedicle screw 12, for example, will bebeneficial for obtaining the necessary leverage for installation andremoval purposes.

FIG. 16 illustrates a cap 260 configured to be connected near the distalend 102 of the first pedicle screw 12. The cap 260 may be constructedfrom a variety of materials, such as a rigid or non-rigid plastic orpolymeric material, metallic or other materials adapted for connectionto the first pedicle screw 12 for penetration through the body of thefirst vertebra 20. In the present aspect it can be seen that the firstend 262 of the cap 260 is substantially conically shaped for promotingpenetration of the first pedicle screw 12 through the first vertebra 20.The cap 260 is advantageously provided where the first pedicle screw 12is provided with a flat surface 264 on the distal end 102 of the firstpedicle screw 12 (see FIG. 14).

A flat surface 264 on the distal end 102 of the first pedicle screw 12further promotes connection and engagement of a tool to the firstpedicle screw 12 for purposes which will be discussed hereinafter. Inthis aspect, the cap 260 will be necessary to reduce or minimize anydamage or aggravation caused by placement of the pedicle screw to anynerves or tissue in or about the area of the first vertebra 20, such asnerves positioned near the pedicle portion of the first vertebra 20.

The cap 260 is shown as a substantially conical member having an innersurface 266 that is provided with one or more notches 268 provided onthe inner surface 266 of the cap 260. The notches 268 are configured tobe tensioningly received by a recess 270 which may be provided on theshaft 16 of the first pedicle screw 12 as shown in FIG. 14. In thismanner, the notches 268 are tensioningly received by one or morerecesses 270 on the shaft 16 which retains the cap 260 sufficientlyengaged near the distal end 102 of the first pedicle screw 12, as wellas promoting easy removal of the cap 260 from the first pedicle screw12. The cap 260 may then be easily removed after placement of the firstpedicle screw 12 for attachment of the guide member 150, as well as atool for retaining and stabilizing the first pedicle screw 12 near thedistal end 102 of the first pedicle screw 12.

FIG. 17 illustrates a tool 280 constructed in accordance with one aspectof the present invention for stabilization of the first pedicle screw 12and the connecting screws, such as the first connecting screw 40. Thetool 280 is provided with a first end 282 having a handle 284 adapted tobe grasped by the hand of an individual. The tool 280 is provided with ashaft 286 extending from the first end to a second end 288. The shaft286 may be of sufficient length to easily utilize the tool 280 forconnection and removal of the vertebral stabilization assembly 10 duringthe surgical process.

A connector 290 is provided on the second end 288 of the tool 280 andconfigured so as to receive, for example, the shaft 16 of the firstpedicle screw 12 provided with one or more grooves 250 on the shaft 16.In this manner, the connector 290 is provided with mating notches 292adapted to be received by the grooves 250 on the shaft 16 of the firstpedicle screw 12.

Once positioned near the distal end 102 of the first pedicle screw 12,the mating notches 292 will receive and engage the first pedicle screw12 so that the tool 280, when rotated by the individual, will have theaffect of rotating the first pedicle screw 12, or, as previouslydiscussed, for stabilizing and retaining the first pedicle screw 12while removing or installing the connecting screws, such as the firstconnecting screw 40. As previously discussed, it may be necessary toutilize the tool 280 to stabilize the first pedicle screw 12,particularly when attempting to remove the rigid connection of the firstconnecting screw 40.

During the removal of the vertebral stabilization assembly 10, the firstconnecting screw 40 will likely be rigidly engaged in the engagingportion 22 of the first pedicle screw 12. When utilizing a first tool,such as the tool 280, to connect to for removal of the first connectingscrew 40, it may be necessary to utilize a second tool, such as the tool280, to engage the distal end 102 of the first pedicle screw 12 toretain the first pedicle screw 12 while removing the first connectingscrew 40. Utilization of one or more of the tools 280 may be beneficialwhile installing, as well as removing the vertebral stabilizationassembly 10.

Furthermore, it will be appreciated that in other aspects the connector290 may be provided on an electric or pneumatic device such as a drillor other apparatus.

FIG. 18 illustrates another aspect of the tool 280 and a differentaspect of the handle 284 as well as the connector 290. In this view, thehandle 284 is more easily grasped by a single hand, such as the handleof a common screw driver, and the connector 290 is configured with aplurality of flat surfaces 294, such as ordinarily found in awrench-wrench. In this manner, the first connecting screw 40 may beprovided with an opening 296 configured to receive the connector 290 forengagement of the tool 280 with the first connecting screw 40.

A number of configurations of the opening 296 on the second end 64 maybe utilized such as one or more grooves 250, and may be provided withassociated tools, such as the tool 280 to establish a rigid engagementof the tool 280 to the connecting screw, such as the first connectingscrew 40, and the first pedicle screw 12. It is within the scope of thepresent invention that the various configurations of the first pediclescrew 12 and the first connecting screw 40 may be interchanged alongwith the configurations of the tool 280 to promote maximum utility forinstallation and removal of the vertebral stabilization assembly. Forexample, the grooves 250 may be provided on the shaft 16 of the firstpedicle screw 12, substantially as shown with respect to FIGS. 14 and15, while the first connecting screw 40 may be provided with a wrenchwrench-type opening 296 or vice versa.

In this manner, one or more configurations of tools may be utilized onone or more of the elements of the vertebral stabilization assembly 10and are within the spirit and scope of the present invention asdisclosed and described herein. Furthermore, it will be appreciated thatthe opening 296 provided on the first connecting screw 40 or on thedistal end 102 of the first pedicle screw 12 may be tapped and threadedopening in a standard or reverse threaded manner for engagement of, forexample, the connector 290 having a threaded connector 290 (not shown)for engagement of the tool 280 to the first connecting screw 40 or thefirst pedicle screw 12.

Also, for example, where the distal end 102 of the first pedicle screw12 is substantially rectangularly shaped, such as in the aspectillustrated in FIG. 11, the connector 290 of the tool 280 may beconfigured to receive the rectangular distal end 102 of the firstpedicle screw 12 or a rectangularly shaped second end 64 of the firstconnecting screw 40. Many other configurations of the distal end 102 ofthe pedicle screw, such as the first pedicle screw 12, and connectingscrews, such as the first connecting screw 40, may be provided andassociated tools 280 having connectors 290 for connection thereto andwill readily suggest themselves to one of ordinary skill in the art andare within the spirit and scope of the present invention described anddisclosed herein.

Furthermore, it is within the spirit and scope of the present inventionthat the first connecting screw 40 may be provided with a double-boltedconfiguration on the threaded portion 66 of the first connecting screw40 and the connector 290 may be a socket-type connection to receive thebolt or bolts for removal of the first connecting screw 40 utilizing thetool 280.

FIG. 19 illustrates a bore screw 300 which may be utilized according toone aspect of the present invention. The bore screw 300 may be providedwith threads (not shown) and may be placed obliquely from the posteriorside 122 of the vertebra 118. The bore screw 300 may be sized such thatthe diameter 302 of the bore screw 300 is sized substantially similar toor smaller than the diameter of the pedicle screw, such as the firstpedicle screw 12. However, it will be appreciated that in other aspectsit may be advantageous for the diameter 302 of the bore screw 300 to besubstantially similar in size to that of the first pedicle screw 12 or,in some instances, for the diameter 302 to be substantially larger.

The bore screw 300 is shown disposed in the pedicle 120 at a desirableangle extending through the vertebra 118. In this manner the bore screw300 may be utilized to create a bore opening (not shown) that may beuseful for placing the pedicle screw, such as the first pedicle screw12, for placement of the pedicle screw from the anterior side 124 of thevertebra 118. In such a procedure the bore screw 300 may bepercutaneously placed in the posterior 122 of the vertebra 118.Thereafter the patient may be rotated such that the anterior 124 of thevertebra 118 is exposed. The bore screw 300 may be provided with acoupling portion 308 adapted for attachment by a tool (not shown) forremoval of the bore screw 300 through the anterior 124 side of thevertebra 118.

In other aspects, the bore screw 300 may be utilized from the anterior124 for tapping the vertebra 118. In other aspects, the coupling portion308 is adapted to engage the guide member 150 for determining alignment.For example, the guide member 150 may be attached to the couplingportion 308 of the bore screw 300 to determine the approximate locationof the connecting screw, such as the first connecting screw 40, andwhere the second end 64 of the first connecting screw 40 will be exposedon the anterior 124 side of vertebra 118.

Attachment of the guide member 150 to the bore screw 300 providesanother advantage of the present aspect in that it may be easilydetermined whether the bore screw 300 is placed at the appropriatelocation in the vertebra 118 or whether another placement will benecessary. This eliminates the need to place the pedicle screw, such asthe first pedicle screw 12, and then determine whether the placement isacceptable.

FIG. 20 illustrates a bore opening 310 which may have been created bythe bore screw 300, or in other embodiments may have been created by adrill or other device capable of creating an opening in the vertebra118. An indicator 312 is shown disposed in the bore opening 310. Theindicator is provided with a shaft 314 and a light 316 provided on oneend of the shaft 314. The light 316 may be a common LED (light emittingdiode) or other light-emitting device which is suitable for thesepurposes, and may include laser light or laser light-emitting diodes.

The shaft 314 may be a substantially rigid shaft of sufficient length toextend down the length of the bore opening 310 and be operable to retainthe light 316 and communicate sufficient electrical power to maintainthe light 316 with power for driving the light 316. In other aspects,the shaft 314 may be a substantially flexible material such as wire orother flexible cording or material.

The indicator 312 is a useful device for indicating the location of thebore opening 310 from the anterior side 124 of the vertebra 118. Aspreviously discussed, a number of soft tissues exist on the right side126 on the anterior side 124 of the vertebra 118. For this reason,whether a bore screw 300 or a drill is utilized to create the boreopening 310 from the posterior side 122, it will be necessary in manycases to prevent penetration of the bore screw 300 or drill completelythrough the vertebra 118 on the anterior side 124 to prevent damage tothe soft tissues on the anterior side 124. The indicator 112 provides anopportunity once the patient has been rotated to retract the softtissues and identify the location of the bore opening 310 from theanterior side 124.

For example, the light 316 shown in the bore opening 310 will beperceptible by the surgeon from the anterior side 124 of the vertebra118. The surgeon may then drill from the anterior side 124 to completethe bore opening 310. Where the bore screw 300 is utilized, the borescrew may be provided with a light, such as the light 316, provided onthe distal end of the bore screw 300 and will be sufficient for thesepurposes. Once the light 316, whether provided on the indicator 312 orthe bore screw 300, has been identified and the bore opening has beendrilled to communicate with the anterior side 124 of the vertebra 118,the indicator 312 or bore screw 300 may then be removed from theanterior side. The indicator 314, such as when the light 316 is a highintensity LED or laser light, may be disposed near the posterior side122 or only slightly within the bore opening 310 such that the lightproduced by the light 316 projects down through the bore opening 310 andis sufficient to identify the bore opening 310 from the anterior side124 of the vertebra 118.

Furthermore, the indicator 312 may, in other aspects, be provided with apneumatic or hydraulically operated capability for punching or extendingthrough the anterior side 124 of the vertebra 118 when the indicator 312is extended through the bore opening 310, such as by utilizing a drill.In this manner, the indicator 312 may be left in place in the boreopening 310 and after the patient has been rotated such that theanterior side 124 of the vertebra 118 has been exposed, the pneumatic orhydraulically-operated indicator 312 may be activated so as to extendthrough the anterior side 124 for communication into the bore opening310.

The indicator 312 may be pulled through the anterior side 124 of thevertebra 118, and in instances where the shaft 314 is a flexiblematerial, it may be severed from, for example, behind the patient, foreasy removal through the anterior side 124. Where the bore screw 300 isutilized and still in place, a tool (not shown) may be connected to thecoupling portion 308 of the bore screw 300 so that the bore screw 300may be removed through the anterior side 124 of the vertebra 118. Thisis advantageous since it eliminates the rotation of the patient forremoval of the bore screw 300 or the indicator 312. The elimination of arotational procedure further reduces the time of the overall procedureand is another advantage of the present aspect of the vertebralstabilization assembly 10 invention disclosed herein.

FIG. 21 illustrates another aspect of the vertebral stabilizationassembly 10 of the present invention. In this aspect the pedicle screw,such as the first pedicle screw 12, is placed in the vertebra 118 fromthe anterior side 124. By utilizing the bore opening 310, the pediclescrew 12 may be more easily and accurately placed into the vertebra 118from the anterior side 124. Placement of the first pedicle screw 12 fromthe anterior side 124 has a number of advantages including that theangle of placement has been previously defined by the bore opening 310.This allows for selection of the first pedicle screw 12 having anengaging portion 22 provided with the appropriate angle 320 with respectto connection of the connecting screw, such as the first connectingscrew 40 (shown in phantom).

It will be appreciated that the exact angle of placement of the firstpedicle screw 12 and resulting angle 320 with respect to the engagingportion 22 and first connecting screw 40 will be unknown until such timethat the first pedicle screw 12 is actually in place in the vertebra118. By previously providing the bore opening 310, the proper pediclescrew may be selected based upon the desired resulting angle 320 soughtfor the resulting placement of the first connecting screw 40. That is,it may be advantageous in certain instances to provide the second end 64of the first connecting screw 40 at a specific location on the left side128 on the anterior side 124 of the vertebra 118. Unless the firstpedicle screw 12 is exactly placed, the resulting location of the secondend 64 of the first connecting screw 40 may be significantly differentthan that desired. For this reason, a number of pedicle screws may beadvantageously provided to the surgeon each having a different lengthand a different engaging portion 22 with respect to the angle ofconnection of the first connecting screw 40 to the engaging portion 22.By having a number of choices available to the surgeon, and based uponthe angle of the bore opening 310, the first pedicle screw 12 may beselected as having an engaging portion 22 that will provide the angle320 that will result in the second end 64 of the first connecting screw40 being positioned at the desired location on the anterior side 124 ofthe vertebra 118.

Anterior side 124 placement of the first pedicle screw 12 within thevertebra 118 provides numerous additional advantages including thedimensions of the first pedicle screw 12 and resulting stability thatmay be achieved from such placement. For example, the first pediclescrew 12, such as that illustrated in FIGS. 4 and 13, may be readilyutilized for these purposes, and may achieve advantageous stabilizationby being placed from the anterior 124 side of the vertebra 118. Forexample, with respect to the first pedicle screw 12 illustrated in FIG.13, it can be seen that the diameter 232 of the reinforced portion 230is slightly smaller than the diameter 246 of the plurality of threads244 according to one aspect.

Since the reinforced portion 230 will not obtain the threadingengagement, it is necessary for the plurality of threads 244 of thefirst pedicle screw 12 to be slightly larger to achieve a satisfactoryanchoring and threading engagement of the first pedicle screw 12.Otherwise, the reinforced portion 230 might have the affect of smoothingthe opening such that the plurality of threads 244 do not successfullyengage within the vertebra 118.

Conversely, anterior side 124 placement of the pedicle screw allows forthe plurality of threads 238 near the distal end 102 of the firstpedicle screw 12 to be of a maximum diameter 240 for optimum anchoringand stabilization of the pedicle screw within the vertebra 118 andparticularly within the pedicle portion 120. At the same time, thediameter 232 of the reinforced portion 230 may be of a maximum diameterfor reinforcement to optimize the connection and engagement of the firstconnecting screw 40 and such structure will not reduce or minimize theengagement of the first pedicle screw 12 with the vertebra 118. Thereason for this is that the plurality of threads 238 will be in front ofthe reinforced portion 230 when anteriorly placed versus behind thereinforced portion 230, as is the case with the plurality of threads 244when the pedicle screw 12 is posteriorly placed. In one aspect, diameter232 of the reinforced portion 230 is similarly sized relative to thediameter 246 of the plurality of threads 244 or any other threadsprovided on the shaft 16. However, numerous configurations of shaft 16sized and thread sizes will readily suggest themselves to one ofordinary skill in the art and are within the spirit and scope of thepresent invention.

It should be appreciated that a variety of configurations of pediclescrews have been disclosed and shown herein and any of the variousconfigurations may be utilized both for posterior placement of the firstpedicle screw 12 as well as for anterior placement of the first pediclescrew 12. Furthermore, it will be appreciated that a number of tools,such as the tool 280 illustrated in FIGS. 17 and 18, have been shown anddescribed and may be readily implemented on the first pedicle screw 12for anterior placement.

FIG. 22 illustrates the first pedicle screw 12 connecting to the guidemember 150 for proper alignment of the connecting screw, such as thefirst connecting screw 40 to the first pedicle screw 12. In one aspect,the present invention is directed to the vertebra stabilization assembly10 wherein the complete procedure may be accomplished from the anteriorside 124 of the vertebra 118. The procedure for such placement mayinclude drilling a hole utilizing a drill or other device or implementthrough the outer surface of the anterior side 124 of the vertebra 118to penetrate the hard outer bone surface.

Thereafter utilizing technology typically employed for such purposes,such as an image intensifier, x-ray and templates, and/or other stealthtechnology, a K-wire or other drill or penetrating implement may beutilized to penetrate in a direction toward the posterior side 122 alonga line 326. The K-wire may be obliquely placed through the vertebralbody into the pedicle 120 on the right side 126. A cannulated drill maybe utilized to drill over the K-wire to ream out a hole or opening forplacement of the first pedicle screw 12 therein. The drill and K-wiremay be removed and the first pedicle screw 12 may be anteriorly placedin the drilled opening substantially along the line 326 for properplacement of the first pedicle screw 12 in the vertebra 118. Thisaspect, as previously discussed, advantageously provides for selecting,in advance, the proper pedicle screw, such as the first pedicle screw12, having the engaging portion 22 to achieve the desired angle ofconnection of the connecting screw, such as the first connecting screw40.

Another advantage of anterior placement of the first pedicle screw 12 isthat it provides the opportunity for stabilization from the posteriorside 122 when such may be desirable. In this aspect, the first pediclescrew 12, such as that illustrated and previously disclosed herein in anumber of different embodiments, may be utilized by placement initiallyfrom the anterior side 124 such that the distal end 102 is anchoredsubstantially in the pedicle 120 portion of the vertebra 118.Thereafter, the first pedicle screw 12 may be utilized for connection ofconnecting members, such as the connecting member 50, for standardposterior anchoring and stabilization when such is necessary because ofa failure to achieve adequate stabilization from the anterior side 124as preferably provided herein.

Under the preferred anterior stabilization and when the first pediclescrew 12 is placed from the anterior side 124 of the vertebra 118, thefirst pedicle screw 12 is provided with a coupling portion 100 near thehead 60 of the first pedicle screw 12, substantially as shown in FIG.22.

Utilization of the vertebral stabilization assembly 10 according to theaspect illustrated in FIG. 22, has the additional advantage ofcompletely eliminating rotation of the patient during the procedure.However, it will be appreciated that there may be certain instances whenit is necessary or useful to rotate the patient for posterior access tothe vertebra 118 and such rotation will not reduce or detract from theadvantages of the vertebral stabilization assembly 10 of the presentinvention in that a significant portion or all of the procedure may beachieved from the anterior side 124 of the vertebra 118. This presents asignificant advantage in that rotation of the patient takes considerabletime and eliminating the necessity for such rotation shortens the timeperiod required for the procedure.

Once the first pedicle screw 12 has been placed on the anterior side 124of the vertebra 118 substantially as shown and discussed above withrespect to FIG. 22, the guide member 150 may be connected to the firstpedicle screw 12 at the coupling portion 100 in a manner similar to thatpreviously shown and described with respect to the coupling portion 100and a guide member 150. Utilization of the guide member 150 as well asthe connection of the connecting screws, such as the first and secondconnecting screws 40 and 42, as well as the bracket 50 remainssubstantially similar to that previously shown and described herein.

It should be appreciated that it is within the scope of the presentinvention to anteriorly place the first pedicle screw 12 on the leftanterior side 124, similar to that shown in FIG. 8 except the firstpedicle screw 12 is placed from the anterior instead of posterior of thevertebra 118. In fact, in some instances, anterior placement on the leftside may be advantageous. The reason that this placement may bepreferable is that the angle of the shaft 16 of the first pedicle screw12 is more shallow with respect to the first connecting screw 40. Thisshallower angle will require a smaller guide member 150 and result inthe surgery being performed in a smaller physical area. Since space islimited in the cavity of the patient, this configuration may be usefulin some circumstances. Also, anterior placement of the pedicle screw onthe left side may be utilized as a salvage when the right side becomesfractured or the desired stabilization is not obtained on the right sideof the vertebra 118.

FIG. 23 illustrates another aspect of the engaging portion 22 of thefirst pedicle screw 12 according to another aspect of the presentinvention. As previously discussed, depending upon the oblique angle ofplacement of the first pedicle screw 12 with respect to the vertebra118, the angle of engagement of the first connecting screw 40 with thefirst pedicle screw 12 may necessarily vary. For this reason, thepresent invention is further directed to an engaging opening 330 whereinthe engaging portion 22 is retained within the shaft 16 of the firstpedicle screw 12.

In this manner, the engaging portion 22 may be retained in the mannersuch that the engaging portion 22 may be rotated to receive the firstconnecting screw 40 at various angles 332. Although two angles 332 areshown, a variety of angles may be achieved utilizing the present aspectof the engaging portion 22. The engaging portion 22 may be retained onbearings or other floating structural devices within the engagingopening 330, such that when the first connecting screw 40 is coupledwith the engaging portion 22, the engaging portion 22 becomes fixed withrespect to the initial angle 332 of engagement.

Such variable positioning of the engaging portion 22 can further beobtained by a hinge or a latch connected to the engaging portion 22 forhinging or latching rotation at the engaging portion 22 within theengaging opening 330. Also, the engaging portion 22 may be provided on arotational or ratcheted body (not shown) within the engaging opening330. It will be appreciated that a wide variety of structures may beutilized for obtaining and achieving an engaging portion, such as theengaging portion 22 to obtain various angulation, such as the angles 332of connection of the first pedicle screw 12 relative to the firstconnecting screw 40 and are well known to those of ordinary skill in theart and are within the spirit and scope of the present invention and forbrevity will not be further discussed herein.

The advantage of the engaging portion 22 adapted for angular adjustmentis that it eliminates the need for a number of pedicle screws havingdifferent engaging portions with different angles for connection to thefirst connecting screw 40. However, it should be appreciated that inother aspects the engaging portion 22 is a fixed and rigid structure forengagement of the first connecting screw 40 and, as such, a plurality ofpedicle screws may be necessary each having a different angle ofengagement of the first connecting screw 40 at the engaging portion 22based upon the angle of placement of the first pedicle screw 12 in thevertebra 118.

Furthermore, according to other aspects of the present invention, it isanticipated that a variety of pedicle screws, such as the first pediclescrew 12, having significantly different lengths will be utilized forvarious adaptations and placements. Also, a variety of pedicle screws,such as the first pedicle screw 12, where the fixed engaging portions 22is available in variety of angles of connection of the connecting screwrelative to the shaft 16 of the first pedicle screw 12.

FIG. 24 illustrates another aspect of the present invention of the firstpedicle screw 12, wherein only a portion of the shaft 16 of the firstpedicle screw 12 is illustrated. In this aspect the shaft 16 is providedwith at least one non-continuous thread 336 extending circumferentiallyabout the shaft 16 of the first pedicle screw 12. In this manner, afirst portion 338 of the non-continuous threads 336 extendcircumferentially about a portion of the shaft 16 while a second portionof the non-continuous threads 336 extend about a second portion of theshaft 16.

A gap 342 is disposed between the first portion 338 and the secondportion 340 of the non-continuous threads 336. The gap is a portion ofthe shaft 16 that is not provided with threads and may be of variouscircumferential dimensions and be suitable for these purposes. It willbe appreciated that frequently the first pedicle screw 12 andparticularly the threads on the shaft 16 may cause aggravation andirritation to nerves adjacent the vertebra 18. Once it has beendetermined that a nerve is aggravated by the placement of the firstpedicle screw 12, adjustment or replacement of the first pedicle screw12 is necessitated. Frequently, this requires completely removing andrelocating the first pedicle screw 12 according to another oblique anglein the vertebra 118. By providing the first pedicle screw 12 having oneor more of the non-continuous threads 336, according to the presentaspect, aggravation of the nerve may be potentially alleviated by only aminor rotation of the first pedicle screw 12 since it is likely that thethread on the shaft 16 may be causing the irritation or aggravation ofthe nerve. Thus, upon a minor or slight rotation of the first pediclescrew 12 the gap 342 will replace, for example, the non-continuousthreads 336 and alleviate the aggravation of the nerve and, thus,eliminate the necessity for completely removing and repositioning thefirst pedicle screw 12. It will be appreciated that the position anddistribution of the non-continuous threads 336 with respect to theirsymmetrical placement may be altered or modified and are within thespirit and scope of the present invention as described and disclosedherein and will readily suggest themselves to one of ordinary skill inthe art.

FIG. 25 illustrates another aspect of the vertebral stabilizationassembly 10 having dual pedicle screws 400 a and 400 b for placement inthe vertebra 118 to provide additional stability. The pedicle screws 400a and 400 b are substantially similar to the first and second pediclescrews 12 and 14 in many aspects. The dual pedicle screws 400 a and 400b, however, are provided with engaging portions 402 a and 402 b relativeto one another such that a connecting screw 404, substantially similarto the first connecting screw 40, may be connected to both the dualpedicle screws 400 a and 400 b. The connecting screw 404 may be providedwith a first end 406 adapted to be received by the engaging portion 402a of the pedicle screw 400 a. The connecting screw 404 is furtherprovided with a shaft 408, at least a portion of which is operative toconnect to the engaging portion 402 b of the pedicle screw 400 b. Thedual pedicle screws 400 a and 400 b must be constructed and configuredsuch that upon placement in the vertebra 118 pedicle screws 400 a and400 b provide for such connection by the connecting screw 404.

In some aspects the engaging portion 402 b of the pedicle screw 400 bmay be an opening sufficient to receive the connecting screw 404 throughthe opening, as well as for engaging the shaft of 408 of the connectingscrew 404. It is readily apparent that this configuration of the dualpedicle screws 400 a and 400 b provides significant vertebral supportand stability. Furthermore, although only the vertebra 118 is shown itshould be understood that the present configuration, including the dualpedicle screws 400 a and 400 b and a connecting screw 404, may beutilized for placement in a plurality of vertebra to provide increasedstabilization for a plurality of vertebra for the purposes previouslydiscussed and disclosed herein.

In another aspect, the present invention provides a fixation tool 430for properly aligning the dual pedicle screws 400 a and 400 b forplacement in the vertebra 118. Accurate alignment and placement of thedual pedicle screws 400 a and 400 b, according to one aspect, may beadvantageously provided by utilizing the fixation tool 430. The fixationtool 430 is provided with alignment members 432 a and 432 b to achievethe proper alignment of the dual pedicle screws 400 a and 400 b in thevertebra 118. The alignment members 432 a and 432 b may be similar tothe alignment member 156 of the guide member 150 previously disclosedand described above.

It may be advantageous, according to other aspects, to provide indiciaon the dual pedicle screws 400 a and 400 b to provide for the properalignment of the pedicle screws 400 a and 400 b. In other aspects thefixation tool 430 may be unnecessary when employing x-ray, stealth, orother imaging technologies to ensure the accurate alignment andplacement of the dual pedicle screws 400 a and 400 b. In other aspects,however, the fixation tool 430 may be used such that the dual pediclescrews 400 a and 400 b may be simultaneously placed to ensure theengaging portions 402 a and 402 b of the dual pedicle screws 400 a and400 b, respectively, are in proper alignment for connection by theconnecting screw 404.

The pedicle screws 400 a and 400 b may also utilize guiding and locatingtechniques, previously discussed above, such that the pedicle screws 400a and 400 b may be placed posteriorly, percutaneously or otherwise, andthe connecting screw 404 may be placed anteriorly. Once the pediclescrews 400 a and 400 b have been inserted, the patient may then berotated. A guide member, such as the guide member 150 may be utilizedfor connection and alignment of the connecting screw 404, as previouslydiscussed above.

Thus, the guide member 150 is coupled, for example, to the pedicle screw400 a such that the alignment member 156 is operable to properly alignthe connecting screw 404 for coupling to the dual pedicle screws 400 aand 400 b. This may include, as previously discussed, drilling a taphole or other guiding hole for accurate placement and alignment of theconnecting screw 404. In any event, the connecting screw 404 may then beconnected to the dual pedicle screws 400 a and 400 b in a configurationsubstantially as illustrated in the present aspect.

FIG. 26 illustrates another aspect of the present invention utilizingdual pedicle screws 400 a and 400 b for anterior placement. It will beappreciated, as previously discussed, that one advantage of the presentinvention is placement of the pedicle screws from the anterior side 124of the vertebra 118. The current aspect illustrates another embodimentof the fixation tool 430 having alignment members 432 a and 432 b foralignment of the dual pedicle screws 400 a and 400 b, respectively, fromthe anterior side 124 of the vertebra 118. The fixation tool 430 mayalso combine the alignment features of the guide member 150 (See FIG.25) to achieve the proper alignment of the connecting screw 404 as well.

In one aspect, the fixation tool 430 may be implemented by determiningthe point 440 on the vertebra 118 to desirably place the connectingscrew 404. A pin, tack or other means may be employed to position andorient the alignment portion 442 which will provide the proper alignmentfor the connecting screw 404. Once the desired placement for theconnecting screw 404 has been located, the dual pedicle screws 400 a and400 b may then be aligned and placed in the vertebra 118 utilizing thealignment members 432 a and 432 b of the alignment tool 430. In someaspects the alignment members 432 a and 432 b may be provided with aninner and an outer barrel (not shown) wherein the inner barrel may beutilized to drill a guide hole in the vertebra 118 and the outer barrelmay then be used to guide the pedicle screws 400 a and 400 b into place.

FIG. 27 illustrates another aspect of the present invention wherein theconnecting screw 404 may be placed across the body of the vertebra 118.In many instances it may be advantageous to position the connectingscrew 404 in such a manner for coupling of the connecting screw 404 toadjacent vertebra similarly stabilized. It is within the spirit andscope of the present invention that such placement of the connectingscrew 404 may still utilize the additional stability provided by one ormore pedicle screws 400 a and 400 b. The pedicle screw 400 b isillustrated in phantom to denote that such placement of the connectingscrew 404 may not necessitate placement of dual pedicle screws 400 a and400 b and only one pedicle screw 400 a may be sufficient to provide thedesired stability in these instances.

Thus, it is apparent that there has been provided, in accordance withthe present invention, a vertebral stabilization assembly and methodthat satisfies one or more of the advantages set forth above. Althoughthe preferred embodiment has been described in detail, it should beunderstood that various changes, substitutions, and alterations can bemade herein without departing from the scope of the present invention,even if all of the advantages identified above are not present. Forexample, the various embodiments shown in the drawings herein illustratethat the present invention may be implemented and embodied in a varietyof different ways that still fall within the scope of the presentinvention.

Also, the techniques, designs, elements, and methods described andillustrated in the preferred embodiment as discrete or separate may becombined or integrated with other techniques, designs, elements, ormethods without departing from the scope of the present invention. Otherexamples of changes, substitutions, and alterations are readilyascertainable by one skilled in the art and could be made withoutdeparting from the spirit and scope of the present invention.

1. A pedicle screw for anchoring in a vertebra, the pedicle screwcomprising: a shaft provided with at least a first and a secondnon-continuous threaded portions extending circumferentially about aportion of the shaft such that at least a first gap is disposed betweenthe first and second non-continuous threaded portions, the at leastfirst gap defining a portion of the shaft between the firstnon-continuous threaded portions and the second non-continuous threadedportions; and a head adjacent one end of the shaft provided with anengaging portion operable to receive engaging rotation by a tool forplacement of the pedicle screw such that at least a portion of thepedicle screw anchors in a pedicle portion of the vertebra.
 2. Thepedicle screw of claim 1, wherein the at least first gap has an outerdiameter that is less than the outer diameter of the firstnon-continuous threaded portions, and less than the outer diameter ofthe second non-continuous threaded portions.
 3. The pedicle screw ofclaim 2, wherein the at least first gap has an outer diameter that isgreater than the outer diameter of the shaft adjacent the first gap. 4.The pedicle screw of claim 1, wherein the first non-continuous threadedportion and the second non-continuous threaded portion are the samesize.
 5. The pedicle screw of claim 1, wherein the first non-continuousthreaded portion has an outer diameter greater than the outer diameterof the second non-continuous threaded portion.
 6. The pedicle screw ofclaim 1, wherein the vertebra is a lumbar vertebra.
 7. The pedicle screwof claim 1, wherein the vertebra is a cervical vertebra.
 8. The pediclescrew of claim 1, wherein the vertebra is a thoracic vertebra.
 9. Apedicle screw for anchoring in a vertebra, the pedicle screw comprising:a shaft provided with at least a first non-continuous threaded portionextending at least partially circumferentially about a first portion ofthe shaft, a second non-continuous threaded portion extending at leastpartially circumferentially about a second portion of the shaft suchthat at least a first gap is disposed between the first and secondnon-continuous threaded portions, the at least first gap defining aportion of the shaft between the first non-continuous threaded portionsand the second non-continuous threaded portions; and a head adjacent oneend of the shaft operable to be rotated with a tool for placement of thepedicle screw such that at least a portion of the pedicle screw isanchored in a pedicle portion of the vertebra.
 10. The pedicle screw ofclaim 9, wherein the at least first gap has an outer diameter that isless than the outer diameter of the first non-continuous threadedportions, and less than the outer diameter of the second non-continuousthreaded portions.
 11. The pedicle screw of claim 10, wherein the atleast first gap has an outer diameter that is greater than the outerdiameter of the shaft adjacent the first gap.
 12. The pedicle screw ofclaim 9, wherein the first non-continuous threaded portion and thesecond non-continuous threaded portion are the same size.
 13. Thepedicle screw of claim 9, wherein the first non-continuous threadedportion has an outer diameter greater than the outer diameter of thesecond non-continuous threaded portion.
 14. The pedicle screw of claim9, wherein the vertebra is a lumbar vertebra.
 15. The pedicle screw ofclaim 9, wherein the vertebra is a cervical vertebra.
 16. The pediclescrew of claim 9, wherein the vertebra is a thoracic vertebra.
 17. Amethod for adjusting a pedicle screw in a vertebra to alleviate nerveirritation, the method comprising: providing a pedicle screw positionedat least partially in a vertebra, the pedicle screw including: a shaftprovided with at least a first and a second non-continuous threadedportions extending circumferentially about a portion of the shaft suchthat at least a first gap is disposed between the first and secondnon-continuous threaded portions, the at least first gap defining aportion of the shaft between the first non-continuous threaded portionsand the second non-continuous threaded portions, and a head adjacent oneend of the shaft operable to be rotated with a tool for placement of thepedicle screw such that at least a portion of the pedicle screw anchorsin a pedicle portion of the vertebra; determining the presence of nerveirritation near the pedicle screw; adjusting the pedicle screw by atleast partially rotating the pedicle screw in the vertebra; andconfirming that the nerve irritation has subsided.
 18. The method ofclaim 17, further comprising: installing a pedicle screw positioned atleast partially in a vertebra.
 19. The method of claim 17, wherein thevertebra is a lumbar vertebra.
 20. The method of claim 17, wherein thevertebra is a cervical vertebra.
 21. The method of claim 17, wherein thevertebra is a thoracic vertebra.